diff --git a/lib/semantic_range.rb b/lib/semantic_range.rb
index fbac4da..0202798 100644
--- a/lib/semantic_range.rb
+++ b/lib/semantic_range.rb
@@ -4,44 +4,46 @@
 require "semantic_range/comparator"
 
 module SemanticRange
-  BUILDIDENTIFIER = /[0-9A-Za-z-]+/
-  BUILD = /(?:\+(#{BUILDIDENTIFIER.source}(?:\.#{BUILDIDENTIFIER.source})*))/
-  NUMERICIDENTIFIER = /0|[1-9]\d*/
-  NUMERICIDENTIFIERLOOSE = /[0-9]+/
-  NONNUMERICIDENTIFIER = /\d*[a-zA-Z-][a-zA-Z0-9-]*/
-  XRANGEIDENTIFIERLOOSE = /#{NUMERICIDENTIFIERLOOSE.source}|x|X|\*/
-  PRERELEASEIDENTIFIERLOOSE =  /(?:#{NUMERICIDENTIFIERLOOSE.source}|#{NONNUMERICIDENTIFIER.source})/
-  PRERELEASELOOSE = /(?:-?(#{PRERELEASEIDENTIFIERLOOSE.source}(?:\.#{PRERELEASEIDENTIFIERLOOSE.source})*))/
-  XRANGEPLAINLOOSE = /[v=\s]*(#{XRANGEIDENTIFIERLOOSE.source})(?:\.(#{XRANGEIDENTIFIERLOOSE.source})(?:\.(#{XRANGEIDENTIFIERLOOSE.source})(?:#{PRERELEASELOOSE.source})?#{BUILD.source}?)?)?/
-  HYPHENRANGELOOSE = /^\s*(#{XRANGEPLAINLOOSE.source})\s+-\s+(#{XRANGEPLAINLOOSE.source})\s*$/
-  PRERELEASEIDENTIFIER = /(?:#{NUMERICIDENTIFIER.source}|#{NONNUMERICIDENTIFIER.source})/
-  PRERELEASE = /(?:-(#{PRERELEASEIDENTIFIER.source}(?:\.#{PRERELEASEIDENTIFIER.source})*))/
-  XRANGEIDENTIFIER = /#{NUMERICIDENTIFIER.source}|x|X|\*/
-  XRANGEPLAIN = /[v=\s]*(#{XRANGEIDENTIFIER.source})(?:\.(#{XRANGEIDENTIFIER.source})(?:\.(#{XRANGEIDENTIFIER.source})(?:#{PRERELEASE.source})?#{BUILD.source}?)?)?/
-  HYPHENRANGE = /^\s*(#{XRANGEPLAIN.source})\s+-\s+(#{XRANGEPLAIN.source})\s*$/
-  MAINVERSIONLOOSE = /(#{NUMERICIDENTIFIERLOOSE.source})\.(#{NUMERICIDENTIFIERLOOSE.source})\.(#{NUMERICIDENTIFIERLOOSE.source})/
-  LOOSEPLAIN = /[v=\s]*#{MAINVERSIONLOOSE.source}#{PRERELEASELOOSE.source}?#{BUILD.source}?/
-  GTLT = /((?:<|>)?=?)/
-  COMPARATORTRIM = /(\s*)#{GTLT.source}\s*(#{LOOSEPLAIN.source}|#{XRANGEPLAIN.source})/
-  LONETILDE = /(?:~>?)/
-  TILDETRIM = /(\s*)#{LONETILDE.source}\s+/
-  LONECARET = /(?:\^)/
-  CARETTRIM = /(\s*)#{LONECARET.source}\s+/
-  STAR = /(<|>)?=?\s*\*/
-  CARET = /^#{LONECARET.source}#{XRANGEPLAIN.source}$/
-  CARETLOOSE = /^#{LONECARET.source}#{XRANGEPLAINLOOSE.source}$/
-  MAINVERSION = /(#{NUMERICIDENTIFIER.source})\.(#{NUMERICIDENTIFIER.source})\.(#{NUMERICIDENTIFIER.source})/
-  FULLPLAIN = /v?#{MAINVERSION.source}#{PRERELEASE.source}?#{BUILD.source}?/
-  FULL = /^#{FULLPLAIN.source}$/
-  LOOSE = /^#{LOOSEPLAIN.source}$/
-  TILDE = /^#{LONETILDE.source}#{XRANGEPLAIN.source}$/
-  TILDELOOSE = /^#{LONETILDE.source}#{XRANGEPLAINLOOSE.source}$/
-  XRANGE = /^#{GTLT.source}\s*#{XRANGEPLAIN.source}$/
-  XRANGELOOSE = /^#{GTLT.source}\s*#{XRANGEPLAINLOOSE.source}$/
-  COMPARATOR = /^#{GTLT.source}\s*(#{FULLPLAIN.source})$|^$/
-  COMPARATORLOOSE = /^#{GTLT.source}\s*(#{LOOSEPLAIN.source})$|^$/
-
-  ANY = {}
+  BUILDIDENTIFIER = /[0-9A-Za-z-]+/.freeze
+  BUILD = /(?:\+(#{BUILDIDENTIFIER.source}(?:\.#{BUILDIDENTIFIER.source})*))/.freeze
+  NUMERICIDENTIFIER = /0|[1-9]\d*/.freeze
+  NUMERICIDENTIFIERLOOSE = /[0-9]+/.freeze
+  NONNUMERICIDENTIFIER = /\d*[a-zA-Z-][a-zA-Z0-9-]*/.freeze
+  XRANGEIDENTIFIERLOOSE = /#{NUMERICIDENTIFIERLOOSE.source}|x|X|\*/.freeze
+  PRERELEASEIDENTIFIERLOOSE =  /(?:#{NUMERICIDENTIFIERLOOSE.source}|#{NONNUMERICIDENTIFIER.source})/.freeze
+  PRERELEASELOOSE = /(?:-?(#{PRERELEASEIDENTIFIERLOOSE.source}(?:\.#{PRERELEASEIDENTIFIERLOOSE.source})*))/.freeze
+  XRANGEPLAINLOOSE = /[v=\s]*(#{XRANGEIDENTIFIERLOOSE.source})(?:\.(#{XRANGEIDENTIFIERLOOSE.source})(?:\.(#{XRANGEIDENTIFIERLOOSE.source})(?:#{PRERELEASELOOSE.source})?#{BUILD.source}?)?)?/.freeze
+  HYPHENRANGELOOSE = /^\s*(#{XRANGEPLAINLOOSE.source})\s+-\s+(#{XRANGEPLAINLOOSE.source})\s*$/.freeze
+  PRERELEASEIDENTIFIER = /(?:#{NUMERICIDENTIFIER.source}|#{NONNUMERICIDENTIFIER.source})/.freeze
+  PRERELEASE = /(?:-(#{PRERELEASEIDENTIFIER.source}(?:\.#{PRERELEASEIDENTIFIER.source})*))/.freeze
+  XRANGEIDENTIFIER = /#{NUMERICIDENTIFIER.source}|x|X|\*/.freeze
+  XRANGEPLAIN = /[v=\s]*(#{XRANGEIDENTIFIER.source})(?:\.(#{XRANGEIDENTIFIER.source})(?:\.(#{XRANGEIDENTIFIER.source})(?:#{PRERELEASE.source})?#{BUILD.source}?)?)?/.freeze
+  HYPHENRANGE = /^\s*(#{XRANGEPLAIN.source})\s+-\s+(#{XRANGEPLAIN.source})\s*$/.freeze
+  MAINVERSIONLOOSE = /(#{NUMERICIDENTIFIERLOOSE.source})\.(#{NUMERICIDENTIFIERLOOSE.source})\.(#{NUMERICIDENTIFIERLOOSE.source})/.freeze
+  LOOSEPLAIN = /[v=\s]*#{MAINVERSIONLOOSE.source}#{PRERELEASELOOSE.source}?#{BUILD.source}?/.freeze
+  GTLT = /((?:<|>)?=?)/.freeze
+  COMPARATORTRIM = /(\s*)#{GTLT.source}\s*(#{LOOSEPLAIN.source}|#{XRANGEPLAIN.source})/.freeze
+  LONETILDE = /(?:~>?)/.freeze
+  TILDETRIM = /(\s*)#{LONETILDE.source}\s+/.freeze
+  LONECARET = /(?:\^)/.freeze
+  CARETTRIM = /(\s*)#{LONECARET.source}\s+/.freeze
+  STAR = /(<|>)?=?\s*\*/.freeze
+  CARET = /^#{LONECARET.source}#{XRANGEPLAIN.source}$/.freeze
+  CARETLOOSE = /^#{LONECARET.source}#{XRANGEPLAINLOOSE.source}$/.freeze
+  MAINVERSION = /(#{NUMERICIDENTIFIER.source})\.(#{NUMERICIDENTIFIER.source})\.(#{NUMERICIDENTIFIER.source})/.freeze
+  FULLPLAIN = /v?#{MAINVERSION.source}#{PRERELEASE.source}?#{BUILD.source}?/.freeze
+  FULL = /^#{FULLPLAIN.source}$/.freeze
+  LOOSE = /^#{LOOSEPLAIN.source}$/.freeze
+  TILDE = /^#{LONETILDE.source}#{XRANGEPLAIN.source}$/.freeze
+  TILDELOOSE = /^#{LONETILDE.source}#{XRANGEPLAINLOOSE.source}$/.freeze
+  XRANGE = /^#{GTLT.source}\s*#{XRANGEPLAIN.source}$/.freeze
+  XRANGELOOSE = /^#{GTLT.source}\s*#{XRANGEPLAINLOOSE.source}$/.freeze
+  COMPARATOR = /^#{GTLT.source}\s*(#{FULLPLAIN.source})$|^$/.freeze
+  COMPARATORLOOSE = /^#{GTLT.source}\s*(#{LOOSEPLAIN.source})$|^$/.freeze
+  GTE0 = /^\s*>=\s*0\.0\.0\s*$/.freeze
+  GTE0PRE = /^\s*>=\s*0\.0\.0-0\s*$/.freeze
+
+  ANY = {}.freeze
 
   MAX_LENGTH = 256
 
@@ -50,12 +52,12 @@ class InvalidVersion < StandardError; end
   class InvalidComparator < StandardError; end
   class InvalidRange < StandardError; end
 
-  def self.ltr?(version, range, loose: false, platform: nil)
-    outside?(version, range, '<', loose: loose, platform: platform)
+  def self.ltr?(version, range, loose: false, platform: nil, include_prerelease: false)
+    outside?(version, range, '<', loose: loose, platform: platform, include_prerelease: include_prerelease)
   end
 
-  def self.gtr?(version, range, loose: false, platform: nil)
-    outside?(version, range, '>', loose: loose, platform: platform)
+  def self.gtr?(version, range, loose: false, platform: nil, include_prerelease: false)
+    outside?(version, range, '>', loose: loose, platform: platform, include_prerelease: include_prerelease)
   end
 
   def self.cmp(a, op, b, loose: false)
@@ -85,11 +87,11 @@ def self.cmp(a, op, b, loose: false)
     end
   end
 
-  def self.outside?(version, range, hilo, loose: false, platform: nil)
+  def self.outside?(version, range, hilo, loose: false, platform: nil, include_prerelease: false)
     version = Version.new(version, loose: loose)
-    range = Range.new(range, loose: loose, platform: platform)
+    range = Range.new(range, loose: loose, platform: platform, include_prerelease: include_prerelease)
 
-    return false if satisfies?(version, range, loose: loose, platform: platform)
+    return false if satisfies?(version, range, loose: loose, platform: platform, include_prerelease: include_prerelease)
 
     case hilo
     when '>'
@@ -148,28 +150,28 @@ def self.outside?(version, range, hilo, loose: false, platform: nil)
     true
   end
 
-  def self.satisfies?(version, range, loose: false, platform: nil)
+  def self.satisfies?(version, range, loose: false, platform: nil, include_prerelease: false)
     return false if !valid_range(range, loose: loose, platform: platform)
-    Range.new(range, loose: loose, platform: platform).test(version)
+    Range.new(range, loose: loose, platform: platform, include_prerelease: include_prerelease).test(version)
   end
 
-  def self.filter(versions, range, loose: false, platform: nil)
-    return [] if !valid_range(range, loose: loose, platform: platform)
+  def self.filter(versions, range, loose: false, platform: nil, include_prerelease: false)
+    return [] if !valid_range(range, loose: loose, platform: platform, include_prerelease: include_prerelease)
 
-    versions.filter { |v| SemanticRange.satisfies?(v, range, loose: loose, platform: platform) }
+    versions.filter { |v| SemanticRange.satisfies?(v, range, loose: loose, platform: platform, include_prerelease: include_prerelease) }
   end
 
-  def self.max_satisfying(versions, range, loose: false, platform: nil)
+  def self.max_satisfying(versions, range, loose: false, platform: nil, include_prerelease: false)
     versions.select { |version|
-      satisfies?(version, range, loose: loose, platform: platform)
+      satisfies?(version, range, loose: loose, platform: platform, include_prerelease: include_prerelease)
     }.sort { |a, b|
       rcompare(a, b, loose: loose)
     }[0] || nil
   end
 
-  def self.valid_range(range, loose: false, platform: nil)
+  def self.valid_range(range, loose: false, platform: nil, include_prerelease: false)
     begin
-      r = Range.new(range, loose: loose, platform: platform).range
+      r = Range.new(range, loose: loose, platform: platform, include_prerelease: include_prerelease).range
       r = '*' if r.nil? || r.empty?
       r
     rescue
@@ -263,8 +265,8 @@ def self.diff(a, b)
     return "prerelease"  if pre_diff
   end
 
-  def self.to_comparators(range, loose: false, platform: nil)
-    Range.new(range, loose: loose, platform: platform).set.map do |comp|
+  def self.to_comparators(range, loose: false, platform: nil, include_prerelease: false)
+    Range.new(range, loose: loose, platform: platform, include_prerelease: include_prerelease).set.map do |comp|
       comp.map(&:to_s)
     end
   end
diff --git a/lib/semantic_range/range.rb b/lib/semantic_range/range.rb
index b5c5ac4..c343801 100644
--- a/lib/semantic_range/range.rb
+++ b/lib/semantic_range/range.rb
@@ -2,11 +2,12 @@ module SemanticRange
   class Range
     attr_reader :loose, :raw, :range, :set, :platform
 
-    def initialize(range, loose: false, platform: nil)
+    def initialize(range, loose: false, platform: nil, include_prerelease: false)
       range = range.raw if range.is_a?(Range)
       @platform = platform
       @raw = range
       @loose = loose
+      @include_prerelease = include_prerelease
       split = range.split(/\s*\|\|\s*/)
       split = ['', ''] if range == '||'
       split = [''] if split == []
@@ -19,6 +20,21 @@ def initialize(range, loose: false, platform: nil)
 
       raise InvalidRange.new(range) if @set.empty? || @set == [[]]
 
+      if @set.any?
+        first = set.first
+        @set = @set.reject { |c| is_null_set(c[0]) }
+        if @set.empty?
+          @set = [first]
+        elsif @set.any?
+          @set.each do |c|
+            if c.length == 1 && is_any(c[0])
+              @set = [c]
+              break
+            end
+          end
+        end
+      end
+
       format
     end
 
@@ -29,15 +45,25 @@ def format
       @range
     end
 
+    def is_null_set(comparator)
+      comparator.value == '<0.0.0-0'
+    end
+
+    def is_any(comparator)
+      comparator.value == ''
+    end
+
     def test(version)
       return false if !version
       version = Version.new(version, loose: @loose) if version.is_a?(String)
       @set.any?{|s| test_set(s, version) }
+    rescue SemanticRange::InvalidVersion
+      false
     end
 
     def test_set(set, version)
       return false if set.any? {|comp| !comp.test(version) }
-      if version.prerelease.length > 0
+      if version.prerelease.length > 0 && !@include_prerelease
         set.each do |comp|
           next if comp.semver == ANY
 
@@ -53,7 +79,8 @@ def test_set(set, version)
 
     def parse_range(range)
       # expand hyphens
-      range = range.gsub(@loose ? HYPHENRANGELOOSE : HYPHENRANGE){ hyphen_replace(Regexp.last_match) }
+      hyphen_range_regex = @loose ? HYPHENRANGELOOSE : HYPHENRANGE
+      range = range.gsub(hyphen_range_regex){ hyphen_replace(Regexp.last_match) }
 
       # comparator trim
       range = range.gsub(COMPARATORTRIM, '\1\2\3')
@@ -71,34 +98,53 @@ def parse_range(range)
       range = range.split(/\s+/).join(' ')
 
       set = range.split(' ').map do |comp|
-        parse_comparator(comp, @loose)
+        parse_comparator(comp)
       end.join(' ').split(/\s+/)
+      set.map! { |comp| replaceGTE0(comp) }
       set = [''] if set == []
 
-      set = set.select{|comp| !!comp.match(COMPARATORLOOSE) } if @loose
+      set = set.select{|comp| comp.match(COMPARATORLOOSE) } if @loose
 
-      set.map{|comp| Comparator.new(comp, @loose) }
+      set.map! {|comp| Comparator.new(comp, @loose) }
+
+      rangeMap = {}
+      set.each do |comp|
+        if is_null_set(comp)
+          return [comp]
+        end
+        rangeMap[comp.value] = comp
+      end
+      if rangeMap.size > 1 && rangeMap.has_key?('')
+        rangeMap.delete('')
+      end
+      rangeMap.values
     end
 
     def isX(id)
       !id || id.downcase == 'x' || id == '*'
     end
 
-    def parse_comparator(comp, loose)
-      comp = replace_carets(comp, loose)
-      comp = replace_tildes(comp, loose)
-      comp = replace_x_ranges(comp, loose)
-      replace_stars(comp, loose)
+    def replaceGTE0(comp)
+      comp.strip.gsub(@include_prerelease ? GTE0PRE : GTE0, '')
+    end
+
+    def parse_comparator(comp)
+      comp = replace_carets(comp)
+      comp = replace_tildes(comp)
+      comp = replace_x_ranges(comp)
+      replace_stars(comp)
     end
 
-    def replace_carets(comp, loose)
+    def replace_carets(comp)
       comp.strip.split(/\s+/).map do |comp|
-        replace_caret(comp, loose)
+        replace_caret(comp)
       end.join(' ')
     end
 
-    def replace_caret(comp, loose)
-      comp.gsub(loose ? CARETLOOSE : CARET) do
+    def replace_caret(comp)
+      z = @include_prerelease ? '-0' : ''
+      comp.gsub(@loose ? CARETLOOSE : CARET) do
+
         match = Regexp.last_match
         mj = match[1]
         m = match[2]
@@ -108,48 +154,45 @@ def replace_caret(comp, loose)
         if isX(mj)
           ''
         elsif isX(m)
-          ">=#{mj}.0.0 <#{(mj.to_i + 1)}.0.0"
+          ">=#{mj}.0.0#{z} <#{(mj.to_i + 1)}.0.0-0"
         elsif isX(p)
           if mj == '0'
-            ">=#{mj}.#{m}.0 <#{mj}.#{(m.to_i + 1)}.0"
+            ">=#{mj}.#{m}.0#{z} <#{mj}.#{(m.to_i + 1)}.0-0"
           else
-            ">=#{mj}.#{m}.0 <#{(mj.to_i + 1)}.0.0"
+            ">=#{mj}.#{m}.0#{z} <#{(mj.to_i + 1)}.0.0-0"
           end
         elsif pr
-          if pr[0] != '-'
-            pr = "-#{pr}"
-          end
           if mj == '0'
             if m == '0'
-              ">=#{mj}.#{m}.#{p}#{pr} <#{mj}.#{m}.#{(p.to_i + 1)}"
+              ">=#{mj}.#{m}.#{p}-#{pr} <#{mj}.#{m}.#{(p.to_i + 1)}-0"
             else
-              ">=#{mj}.#{m}.#{p}#{pr} <#{mj}.#{(m.to_i + 1)}.0"
+              ">=#{mj}.#{m}.#{p}-#{pr} <#{mj}.#{(m.to_i + 1)}.0-0"
             end
           else
-            ">=#{mj}.#{m}.#{p}#{pr} <#{(mj.to_i + 1)}.0.0"
+            ">=#{mj}.#{m}.#{p}-#{pr} <#{(mj.to_i + 1)}.0.0-0"
           end
         else
           if mj == '0'
             if m == '0'
-              ">=#{mj}.#{m}.#{p} <#{mj}.#{m}.#{(p.to_i + 1)}"
+              ">=#{mj}.#{m}.#{p}#{z} <#{mj}.#{m}.#{(p.to_i + 1)}-0"
             else
-              ">=#{mj}.#{m}.#{p} <#{mj}.#{(m.to_i + 1)}.0"
+              ">=#{mj}.#{m}.#{p}#{z} <#{mj}.#{(m.to_i + 1)}.0-0"
             end
           else
-            ">=#{mj}.#{m}.#{p} <#{(mj.to_i + 1)}.0.0"
+            ">=#{mj}.#{m}.#{p} <#{(mj.to_i + 1)}.0.0-0"
           end
         end
       end
     end
 
-    def replace_tildes(comp, loose)
+    def replace_tildes(comp)
       comp.strip.split(/\s+/).map do |comp|
-        replace_tilde(comp, loose)
+        replace_tilde(comp)
       end.join(' ')
     end
 
-    def replace_tilde(comp, loose)
-      comp.gsub(loose ? TILDELOOSE : TILDE) do
+    def replace_tilde(comp)
+      comp.gsub(@loose ? TILDELOOSE : TILDE) do
         match = Regexp.last_match
         mj = match[1]
         m = match[2]
@@ -159,39 +202,37 @@ def replace_tilde(comp, loose)
         if isX(mj)
           ''
         elsif isX(m)
-          ">=#{mj}.0.0 <#{(mj.to_i + 1)}.0.0"
+          ">=#{mj}.0.0 <#{(mj.to_i + 1)}.0.0-0"
         elsif isX(p)
           if ['Rubygems', 'Packagist'].include?(platform)
             ">=#{mj}.#{m}.0 <#{mj.to_i+1}.0.0"
           else
-            ">=#{mj}.#{m}.0 <#{mj}.#{(m.to_i + 1)}.0"
+            ">=#{mj}.#{m}.0 <#{mj}.#{(m.to_i + 1)}.0-0"
           end
-
         elsif pr
-          pr = '-' + pr if (pr[0] != '-')
-          ">=#{mj}.#{m}.#{p}#{pr} <#{mj}.#{(m.to_i + 1)}.0"
+          pr = '-' + pr if pr[0] != '-'
+          ">=#{mj}.#{m}.#{p}#{pr} <#{mj}.#{(m.to_i + 1)}.0-0"
         else
-          ">=#{mj}.#{m}.#{p} <#{mj}.#{(m.to_i + 1)}.0"
+          ">=#{mj}.#{m}.#{p} <#{mj}.#{(m.to_i + 1)}.0-0"
         end
       end
     end
 
-    def replace_x_ranges(comp, loose)
+    def replace_x_ranges(comp)
       comp.strip.split(/\s+/).map do |comp|
-        replace_x_range(comp, loose)
+        replace_x_range(comp)
       end.join(' ')
     end
 
-    def replace_x_range(comp, loose)
+    def replace_x_range(comp)
       comp = comp.strip
-      comp.gsub(loose ? XRANGELOOSE : XRANGE) do
+      comp.gsub(@loose ? XRANGELOOSE : XRANGE) do
         match = Regexp.last_match
         ret = match[0]
         gtlt = match[1]
         mj = match[2]
         m = match[3]
         p = match[4]
-        pr = match[5]
 
         xM = isX(mj)
         xm = xM || isX(m)
@@ -200,9 +241,11 @@ def replace_x_range(comp, loose)
 
         gtlt = '' if gtlt == '=' && anyX
 
+        pr = @include_prerelease ? '-0' : ''
+
         if xM
           if gtlt == '>' || gtlt == '<'
-            '<0.0.0'
+            '<0.0.0-0'
           else
             '*'
           end
@@ -229,18 +272,20 @@ def replace_x_range(comp, loose)
             end
           end
 
-          "#{gtlt}#{mj}.#{m}.#{p}"
+          pr = '-0' if gtlt == '<'
+
+          "#{gtlt}#{mj}.#{m}.#{p}#{pr}"
         elsif xm
-          ">=#{mj}.0.0 <#{(mj.to_i + 1)}.0.0"
+          ">=#{mj}.0.0#{pr} <#{(mj.to_i + 1)}.0.0-0"
         elsif xp
-          ">=#{mj}.#{m}.0 <#{mj}.#{(m.to_i + 1)}.0"
+          ">=#{mj}.#{m}.0#{pr} <#{mj}.#{(m.to_i + 1)}.0-0"
         else
           ret
         end
       end
     end
 
-    def replace_stars(comp, loose)
+    def replace_stars(comp)
       comp.strip.gsub(STAR, '')
     end
 
@@ -261,21 +306,25 @@ def hyphen_replace(match)
       if isX(fM)
         from = ''
       elsif isX(fm)
-        from = ">=#{fM}.0.0"
+        from = ">=#{fM}.0.0#{@include_prerelease ? '-0' : ''}"
       elsif isX(fp)
-        from = ">=#{fM}.#{fm}.0"
-      else
+        from = ">=#{fM}.#{fm}.0#{@include_prerelease ? '-0' : ''}"
+      elsif fpr
         from = ">=#{from}"
+      else
+        from = ">=#{from}#{@include_prerelease ? '-0' : ''}"
       end
 
       if isX(tM)
         to = ''
       elsif isX(tm)
-        to = "<#{(tM.to_i + 1)}.0.0"
+        to = "<#{(tM.to_i + 1)}.0.0-0"
       elsif isX(tp)
-        to = "<#{tM}.#{(tm.to_i + 1)}.0"
+        to = "<#{tM}.#{(tm.to_i + 1)}.0-0"
       elsif tpr
         to = "<=#{tM}.#{tm}.#{tp}-#{tpr}"
+      elsif @include_prerelease
+        to = "<#{tM}.#{tm}.#{tp.to_i + 1}-0"
       else
         to = "<=#{to}"
       end
diff --git a/spec/rubygems_ranges_spec.rb b/spec/rubygems_ranges_spec.rb
index fa0f268..07684e3 100644
--- a/spec/rubygems_ranges_spec.rb
+++ b/spec/rubygems_ranges_spec.rb
@@ -109,6 +109,17 @@
     end
   end
 
+  it 'range with prerelease' do
+    [
+      ['>=1 <3', '1.23.0-20210103.1434']
+    ].each do |tuple|
+      range = tuple[0]
+      version = tuple[1]
+      loose = tuple[2]
+      expect(SemanticRange.satisfies?(version, range, loose: loose, include_prerelease: true)).to eq(true), "#{tuple}"
+    end
+  end
+
   it 'negative range for rubygems/packagist' do
     [
       ['1.0.0 - 2.0.0', '2.2.3'],
@@ -195,14 +206,10 @@
       ['>=*', '*'],
       ['', '*'],
       ['*', '*'],
-      ['*', '*'],
       ['>=1.0.0', '>=1.0.0'],
       ['>1.0.0', '>1.0.0'],
       ['<=2.0.0', '<=2.0.0'],
-      ['1', '>=1.0.0 <2.0.0'],
-      ['<=2.0.0', '<=2.0.0'],
-      ['<=2.0.0', '<=2.0.0'],
-      ['<2.0.0', '<2.0.0'],
+      ['1', '>=1.0.0 <2.0.0-0'],
       ['<2.0.0', '<2.0.0'],
       ['>= 1.0.0', '>=1.0.0'],
       ['>=  1.0.0', '>=1.0.0'],
@@ -213,54 +220,48 @@
       ['<= 2.0.0', '<=2.0.0'],
       ['<=  2.0.0', '<=2.0.0'],
       ['<    2.0.0', '<2.0.0'],
-      ['<	2.0.0', '<2.0.0'],
-      ['>=0.1.97', '>=0.1.97'],
+      ["<\t2.0.0", '<2.0.0'],
       ['>=0.1.97', '>=0.1.97'],
       ['0.1.20 || 1.2.4', '0.1.20||1.2.4'],
       ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
-      ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
-      ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
-      ['||', '||'],
-      ['2.x.x', '>=2.0.0 <3.0.0'],
-      ['1.2.x', '>=1.2.0 <1.3.0'],
-      ['1.2.x || 2.x', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
-      ['1.2.x || 2.x', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
+      ['||', '*'],
+      ['2.x.x', '>=2.0.0 <3.0.0-0'],
+      ['1.2.x', '>=1.2.0 <1.3.0-0'],
+      ['1.2.x || 2.x', '>=1.2.0 <1.3.0-0||>=2.0.0 <3.0.0-0'],
       ['x', '*'],
-      ['2.*.*', '>=2.0.0 <3.0.0'],
-      ['1.2.*', '>=1.2.0 <1.3.0'],
-      ['1.2.* || 2.*', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
-      ['*', '*'],
-      ['2', '>=2.0.0 <3.0.0'],
-      ['2.3', '>=2.3.0 <2.4.0'],
+      ['2.*.*', '>=2.0.0 <3.0.0-0'],
+      ['1.2.*', '>=1.2.0 <1.3.0-0'],
+      ['1.2.* || 2.*', '>=1.2.0 <1.3.0-0||>=2.0.0 <3.0.0-0'],
+      ['2', '>=2.0.0 <3.0.0-0'],
+      ['2.3', '>=2.3.0 <2.4.0-0'],
       ['~2.4', '>=2.4.0 <3.0.0'],
-      ['~>3.2.1', '>=3.2.1 <3.3.0'],
-      ['~1', '>=1.0.0 <2.0.0'],
-      ['~>1', '>=1.0.0 <2.0.0'],
-      ['~> 1', '>=1.0.0 <2.0.0'],
+      ['~>3.2.1', '>=3.2.1 <3.3.0-0'],
+      ['~1', '>=1.0.0 <2.0.0-0'],
+      ['~>1', '>=1.0.0 <2.0.0-0'],
+      ['~> 1', '>=1.0.0 <2.0.0-0'],
       ['~1.0', '>=1.0.0 <2.0.0'],
       ['~ 1.0', '>=1.0.0 <2.0.0'],
-      ['^0', '>=0.0.0 <1.0.0'],
-      ['^ 1', '>=1.0.0 <2.0.0'],
-      ['^0.1', '>=0.1.0 <0.2.0'],
-      ['^1.0', '>=1.0.0 <2.0.0'],
-      ['^1.2', '>=1.2.0 <2.0.0'],
-      ['^0.0.1', '>=0.0.1 <0.0.2'],
-      ['^0.0.1-beta', '>=0.0.1-beta <0.0.2'],
-      ['^0.1.2', '>=0.1.2 <0.2.0'],
-      ['^1.2.3', '>=1.2.3 <2.0.0'],
-      ['^1.2.3-beta.4', '>=1.2.3-beta.4 <2.0.0'],
-      ['<1', '<1.0.0'],
-      ['< 1', '<1.0.0'],
+      ['^0', '<1.0.0-0'],
+      ['^ 1', '>=1.0.0 <2.0.0-0'],
+      ['^0.1', '>=0.1.0 <0.2.0-0'],
+      ['^1.0', '>=1.0.0 <2.0.0-0'],
+      ['^1.2', '>=1.2.0 <2.0.0-0'],
+      ['^0.0.1', '>=0.0.1 <0.0.2-0'],
+      ['^0.0.1-beta', '>=0.0.1-beta <0.0.2-0'],
+      ['^0.1.2', '>=0.1.2 <0.2.0-0'],
+      ['^1.2.3', '>=1.2.3 <2.0.0-0'],
+      ['^1.2.3-beta.4', '>=1.2.3-beta.4 <2.0.0-0'],
+      ['<1', '<1.0.0-0'],
+      ['< 1', '<1.0.0-0'],
       ['>=1', '>=1.0.0'],
       ['>= 1', '>=1.0.0'],
-      ['<1.2', '<1.2.0'],
-      ['< 1.2', '<1.2.0'],
-      ['1', '>=1.0.0 <2.0.0'],
+      ['<1.2', '<1.2.0-0'],
+      ['< 1.2', '<1.2.0-0'],
       ['>01.02.03', '>1.2.3', true],
       ['>01.02.03', nil],
-      ['~1.2.3beta', '>=1.2.3-beta <1.3.0', true],
+      ['~1.2.3beta', '>=1.2.3-beta <1.3.0-0', true],
       ['~1.2.3beta', nil],
-      ['^ 1.2 ^ 1', '>=1.2.0 <2.0.0 >=1.0.0 <2.0.0']
+      ['^ 1.2 ^ 1', '>=1.2.0 <2.0.0-0 >=1.0.0']
     ].each do |tuple|
       pre = tuple[0]
       wanted = tuple[1]
@@ -291,17 +292,10 @@
       ['>=*', [['']]],
       ['', [['']]],
       ['*', [['']]],
-      ['*', [['']]],
-      ['>=1.0.0', [['>=1.0.0']]],
       ['>=1.0.0', [['>=1.0.0']]],
-      ['>=1.0.0', [['>=1.0.0']]],
-      ['>1.0.0', [['>1.0.0']]],
       ['>1.0.0', [['>1.0.0']]],
       ['<=2.0.0', [['<=2.0.0']]],
-      ['1', [['>=1.0.0', '<2.0.0']]],
-      ['<=2.0.0', [['<=2.0.0']]],
-      ['<=2.0.0', [['<=2.0.0']]],
-      ['<2.0.0', [['<2.0.0']]],
+      ['1', [['>=1.0.0', '<2.0.0-0']]],
       ['<2.0.0', [['<2.0.0']]],
       ['>= 1.0.0', [['>=1.0.0']]],
       ['>=  1.0.0', [['>=1.0.0']]],
@@ -314,46 +308,40 @@
       ['<    2.0.0', [['<2.0.0']]],
       ["<\t2.0.0", [['<2.0.0']]],
       ['>=0.1.97', [['>=0.1.97']]],
-      ['>=0.1.97', [['>=0.1.97']]],
       ['0.1.20 || 1.2.4', [['0.1.20'], ['1.2.4']]],
       ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['||', [[''], ['']]],
-      ['2.x.x', [['>=2.0.0', '<3.0.0']]],
-      ['1.2.x', [['>=1.2.0', '<1.3.0']]],
-      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
+      ['||', [['']]],
+      ['2.x.x', [['>=2.0.0', '<3.0.0-0']]],
+      ['1.2.x', [['>=1.2.0', '<1.3.0-0']]],
+      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0-0'], ['>=2.0.0', '<3.0.0-0']]],
       ['x', [['']]],
-      ['2.*.*', [['>=2.0.0', '<3.0.0']]],
-      ['1.2.*', [['>=1.2.0', '<1.3.0']]],
-      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['*', [['']]],
-      ['2', [['>=2.0.0', '<3.0.0']]],
-      ['2.3', [['>=2.3.0', '<2.4.0']]],
+      ['2.*.*', [['>=2.0.0', '<3.0.0-0']]],
+      ['1.2.*', [['>=1.2.0', '<1.3.0-0']]],
+      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0-0'], ['>=2.0.0', '<3.0.0-0']]],
+      ['2', [['>=2.0.0', '<3.0.0-0']]],
+      ['2.3', [['>=2.3.0', '<2.4.0-0']]],
       ['~2.4', [['>=2.4.0', '<3.0.0']]],
-      ['~>3.2.1', [['>=3.2.1', '<3.3.0']]],
-      ['~1', [['>=1.0.0', '<2.0.0']]],
-      ['~>1', [['>=1.0.0', '<2.0.0']]],
-      ['~> 1', [['>=1.0.0', '<2.0.0']]],
+      ['~>3.2.1', [['>=3.2.1', '<3.3.0-0']]],
+      ['~1', [['>=1.0.0', '<2.0.0-0']]],
+      ['~>1', [['>=1.0.0', '<2.0.0-0']]],
+      ['~> 1', [['>=1.0.0', '<2.0.0-0']]],
       ['~1.0', [['>=1.0.0', '<2.0.0']]],
       ['~ 1.0', [['>=1.0.0', '<2.0.0']]],
-      ['~ 1.0.3', [['>=1.0.3', '<1.1.0']]],
-      ['~> 1.0.3', [['>=1.0.3', '<1.1.0']]],
-      ['<1', [['<1.0.0']]],
-      ['< 1', [['<1.0.0']]],
+      ['~ 1.0.3', [['>=1.0.3', '<1.1.0-0']]],
+      ['~> 1.0.3', [['>=1.0.3', '<1.1.0-0']]],
+      ['<1', [['<1.0.0-0']]],
+      ['< 1', [['<1.0.0-0']]],
       ['>=1', [['>=1.0.0']]],
       ['>= 1', [['>=1.0.0']]],
-      ['<1.2', [['<1.2.0']]],
-      ['< 1.2', [['<1.2.0']]],
-      ['1', [['>=1.0.0', '<2.0.0']]],
-      ['1 2', [['>=1.0.0', '<2.0.0', '>=2.0.0', '<3.0.0']]],
+      ['<1.2', [['<1.2.0-0']]],
+      ['< 1.2', [['<1.2.0-0']]],
+      ['1', [['>=1.0.0', '<2.0.0-0']]],
+      ['1 2', [['>=1.0.0', '<2.0.0-0', '>=2.0.0', '<3.0.0-0']]],
       ['1.2 - 3.4.5', [['>=1.2.0', '<=3.4.5']]],
-      ['1.2.3 - 3.4', [['>=1.2.3', '<3.5.0']]],
-      ['1.2.3 - 3', [['>=1.2.3', '<4.0.0']]],
-      ['>*', [['<0.0.0']]],
-      ['<*', [['<0.0.0']]]
+      ['1.2.3 - 3.4', [['>=1.2.3', '<3.5.0-0']]],
+      ['1.2.3 - 3', [['>=1.2.3', '<4.0.0-0']]],
+      ['>*', [['<0.0.0-0']]],
+      ['<*', [['<0.0.0-0']]]
     ].each do |v|
       pre, wanted = v
       found = SemanticRange.to_comparators(pre, loose: false, platform: 'Rubygems')
diff --git a/spec/semantic_range_gtr_spec.rb b/spec/semantic_range_gtr_spec.rb
index d96ba4f..a08d1bb 100644
--- a/spec/semantic_range_gtr_spec.rb
+++ b/spec/semantic_range_gtr_spec.rb
@@ -2,7 +2,7 @@
 
 describe SemanticRange do
   it 'gtr' do
-    # [version, range, loose]
+    # [version, range, options]
     # Version should be greater than range
     expect(SemanticRange.gtr?('1.3.0', '~1.2.2')).to eq(true)
     expect(SemanticRange.gtr?('0.7.1-1', '~0.6.1-1')).to eq(true)
@@ -70,10 +70,11 @@
     expect(SemanticRange.gtr?('1.0.0beta', '< 1', loose: true)).to eq(true)
     expect(SemanticRange.gtr?('0.8.2', '=0.7.x')).to eq(true)
     expect(SemanticRange.gtr?('0.7.2', '<0.7.x')).to eq(true)
+    expect(SemanticRange.gtr?('0.7.2-beta', '<0.7.x')).to eq(true)
   end
 
   it 'negative gtr' do
-    # [version, range, loose]
+    # [version, range, options]
     # Version should NOT be greater than range
     expect(SemanticRange.gtr?('0.6.1-1', '~0.6.1-1')).to eq(false)
     expect(SemanticRange.gtr?('1.2.3', '1.0.0 - 2.0.0')).to eq(false)
@@ -156,5 +157,6 @@
     expect(SemanticRange.gtr?('1.0.0beta', '^0.1.0 || ~3.0.1 || 5.0.0', loose: true)).to eq(false)
     expect(SemanticRange.gtr?('5.0.0-0', '^0.1.0 || ~3.0.1 || 5.0.0', loose: true)).to eq(false)
     expect(SemanticRange.gtr?('3.5.0', '^0.1.0 || ~3.0.1 || >4 <=5.0.0')).to eq(false)
+    expect(SemanticRange.gtr?('0.7.2-beta', '0.7.x', include_prerelease: true)).to eq(false)
   end
 end
diff --git a/spec/semantic_range_ltr_spec.rb b/spec/semantic_range_ltr_spec.rb
index 0b17c8e..8a30eaa 100644
--- a/spec/semantic_range_ltr_spec.rb
+++ b/spec/semantic_range_ltr_spec.rb
@@ -74,92 +74,98 @@
   end
 
   it 'negative ltr' do
-    # [version, range, loose]
+    # [version, range, options]
     # Version should NOT be less than range
-    expect(SemanticRange.ltr?('1.2.4', '1.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.0', '~ 1.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.6.1-1', '~0.6.1-1')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.0.0 - 2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('2.9.9', '1.0.0 - 2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.4', '>=*')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '*')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '>=1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.1', '>=1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.0', '>=1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.1', '>1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.0', '>1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('2.0.0', '<=2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.9999.9999', '<=2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.9', '<=2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.9999.9999', '<2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.9', '<2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '>= 1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.1', '>=  1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.0', '>=   1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.1', '> 1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.0', '>  1.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('2.0.0', '<=   2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.9999.9999', '<= 2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.9', '<=  2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.9999.9999', '<    2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.9', "<\t2.0.0")).to eq(false)
-    expect(SemanticRange.ltr?('v0.1.97', '>=0.1.97')).to eq(false)
-    expect(SemanticRange.ltr?('0.1.97', '>=0.1.97')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.4', '0.1.20 || 1.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.4', '0.1.20 || >1.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '0.1.20 || 1.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('0.1.20', '0.1.20 || 1.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('0.0.0', '>=0.2.3 || <0.0.1')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.3', '>=0.2.3 || <0.0.1')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.4', '>=0.2.3 || <0.0.1')).to eq(false)
-    expect(SemanticRange.ltr?('1.3.4', '||')).to eq(false)
-    expect(SemanticRange.ltr?('2.1.3', '2.x.x')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.2.x')).to eq(false)
-    expect(SemanticRange.ltr?('2.1.3', '1.2.x || 2.x')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.2.x || 2.x')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', 'x')).to eq(false)
-    expect(SemanticRange.ltr?('2.1.3', '2.*.*')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.2.*')).to eq(false)
-    expect(SemanticRange.ltr?('2.1.3', '1.2.* || 2.*')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.2.* || 2.*')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '1.2.* || 2.*')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '*')).to eq(false)
-    expect(SemanticRange.ltr?('2.1.2', '2')).to eq(false)
-    expect(SemanticRange.ltr?('2.3.1', '2.3')).to eq(false)
-    expect(SemanticRange.ltr?('2.4.0', '~2.4')).to eq(false) # >=2.4.0 <2.5.))
-    expect(SemanticRange.ltr?('2.4.5', '~2.4')).to eq(false)
-    expect(SemanticRange.ltr?('3.2.2', '~>3.2.1')).to eq(false) # >=3.2.1 <3.3.))
-    expect(SemanticRange.ltr?('1.2.3', '~1')).to eq(false) # >=1.0.0 <2.0.))
-    expect(SemanticRange.ltr?('1.2.3', '~>1')).to eq(false)
-    expect(SemanticRange.ltr?('1.2.3', '~> 1')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.2', '~1.0')).to eq(false) # >=1.0.0 <1.1.))
-    expect(SemanticRange.ltr?('1.0.2', '~ 1.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '>=1')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '>= 1')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.1', '<1.2')).to eq(false)
-    expect(SemanticRange.ltr?('1.1.1', '< 1.2')).to eq(false)
-    expect(SemanticRange.ltr?('0.5.5', '~v0.5.4-pre')).to eq(false)
-    expect(SemanticRange.ltr?('0.5.4', '~v0.5.4-pre')).to eq(false)
-    expect(SemanticRange.ltr?('0.7.2', '=0.7.x')).to eq(false)
-    expect(SemanticRange.ltr?('0.7.2', '>=0.7.x')).to eq(false)
-    expect(SemanticRange.ltr?('0.6.2', '<=0.7.x')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.5', '>0.2.3 >0.2.4 <=0.2.5')).to eq(false)
-    expect(SemanticRange.ltr?('0.2.4', '>=0.2.3 <=0.2.4')).to eq(false)
-    expect(SemanticRange.ltr?('2.0.0', '1.0.0 - 2.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('4.0.0', '^3.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('2.0.0', '^1.0.0 || ~2.0.1')).to eq(false)
-    expect(SemanticRange.ltr?('3.2.0', '^0.1.0 || ~3.0.1 || 5.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0beta', '^0.1.0 || ~3.0.1 || 5.0.0', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('5.0.0-0', '^0.1.0 || ~3.0.1 || 5.0.0', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('3.5.0', '^0.1.0 || ~3.0.1 || >4 <=5.0.0')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0beta', '^1.0.0alpha', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0beta', '~1.0.0alpha', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0beta', '^1.0.0-alpha', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0beta', '~1.0.0-alpha', loose: true)).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0-beta', '^1.0.0-alpha')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0-beta', '~1.0.0-alpha')).to eq(false)
-    expect(SemanticRange.ltr?('1.0.0', '=0.1.0')).to eq(false)
+    [['~ 1.0', '1.1.0'],
+     ['~0.6.1-1', '0.6.1-1'],
+     ['1.0.0 - 2.0.0', '1.2.3'],
+     ['1.0.0 - 2.0.0', '2.9.9'],
+     ['1.0.0', '1.0.0'],
+     ['>=*', '0.2.4'],
+     ['', '1.0.0', loose: true],
+     ['*', '1.2.3'],
+     ['>=1.0.0', '1.0.0'],
+     ['>=1.0.0', '1.0.1'],
+     ['>=1.0.0', '1.1.0'],
+     ['>1.0.0', '1.0.1'],
+     ['>1.0.0', '1.1.0'],
+     ['<=2.0.0', '2.0.0'],
+     ['<=2.0.0', '1.9999.9999'],
+     ['<=2.0.0', '0.2.9'],
+     ['<2.0.0', '1.9999.9999'],
+     ['<2.0.0', '0.2.9'],
+     ['>= 1.0.0', '1.0.0'],
+     ['>=  1.0.0', '1.0.1'],
+     ['>=   1.0.0', '1.1.0'],
+     ['> 1.0.0', '1.0.1'],
+     ['>  1.0.0', '1.1.0'],
+     ['<=   2.0.0', '2.0.0'],
+     ['<= 2.0.0', '1.9999.9999'],
+     ['<=  2.0.0', '0.2.9'],
+     ['<    2.0.0', '1.9999.9999'],
+     ["<\t2.0.0", '0.2.9'],
+     ['>=0.1.97', 'v0.1.97'],
+     ['>=0.1.97', '0.1.97'],
+     ['0.1.20 || 1.2.4', '1.2.4'],
+     ['0.1.20 || >1.2.4', '1.2.4'],
+     ['0.1.20 || 1.2.4', '1.2.3'],
+     ['0.1.20 || 1.2.4', '0.1.20'],
+     ['>=0.2.3 || <0.0.1', '0.0.0'],
+     ['>=0.2.3 || <0.0.1', '0.2.3'],
+     ['>=0.2.3 || <0.0.1', '0.2.4'],
+     ['||', '1.3.4'],
+     ['2.x.x', '2.1.3'],
+     ['1.2.x', '1.2.3'],
+     ['1.2.x || 2.x', '2.1.3'],
+     ['1.2.x || 2.x', '1.2.3'],
+     ['x', '1.2.3'],
+     ['2.*.*', '2.1.3'],
+     ['1.2.*', '1.2.3'],
+     ['1.2.* || 2.*', '2.1.3'],
+     ['1.2.* || 2.*', '1.2.3'],
+     ['1.2.* || 2.*', '1.2.3'],
+     ['*', '1.2.3'],
+     ['2', '2.1.2'],
+     ['2.3', '2.3.1'],
+     ['~2.4', '2.4.0'], # >=2.4.0 <2.5.0
+     ['~2.4', '2.4.5'],
+     ['~>3.2.1', '3.2.2'], # >=3.2.1 <3.3.0
+     ['~1', '1.2.3'], # >=1.0.0 <2.0.0
+     ['~>1', '1.2.3'],
+     ['~> 1', '1.2.3'],
+     ['~1.0', '1.0.2'], # >=1.0.0 <1.1.0
+     ['~ 1.0', '1.0.2'],
+     ['>=1', '1.0.0'],
+     ['>= 1', '1.0.0'],
+     ['<1.2', '1.1.1'],
+     ['< 1.2', '1.1.1'],
+     ['~v0.5.4-pre', '0.5.5'],
+     ['~v0.5.4-pre', '0.5.4'],
+     ['=0.7.x', '0.7.2'],
+     ['>=0.7.x', '0.7.2'],
+     ['<=0.7.x', '0.6.2'],
+     ['>0.2.3 >0.2.4 <=0.2.5', '0.2.5'],
+     ['>=0.2.3 <=0.2.4', '0.2.4'],
+     ['1.0.0 - 2.0.0', '2.0.0'],
+     ['^3.0.0', '4.0.0'],
+     ['^1.0.0 || ~2.0.1', '2.0.0'],
+     ['^0.1.0 || ~3.0.1 || 5.0.0', '3.2.0'],
+     ['^0.1.0 || ~3.0.1 || 5.0.0', '1.0.0beta', loose: true],
+     ['^0.1.0 || ~3.0.1 || 5.0.0', '5.0.0-0', loose: true],
+     ['^0.1.0 || ~3.0.1 || >4 <=5.0.0', '3.5.0'],
+     ['^1.0.0alpha', '1.0.0beta', loose: true],
+     ['~1.0.0alpha', '1.0.0beta', loose: true],
+     ['^1.0.0-alpha', '1.0.0beta', loose: true],
+     ['~1.0.0-alpha', '1.0.0beta', loose: true],
+     ['^1.0.0-alpha', '1.0.0-beta'],
+     ['~1.0.0-alpha', '1.0.0-beta'],
+     ['=0.1.0', '1.0.0'],
+     ['>1.2.3', '1.3.0-alpha', include_prerelease: true]
+    ].each do |tuple|
+      range = tuple[0]
+      version = tuple[1]
+      options = tuple[2] || {}
+      expect(SemanticRange.ltr?(version, range, **options)).to eq(false)
+    end
   end
 end
diff --git a/spec/semantic_range_spec.rb b/spec/semantic_range_spec.rb
index 122c3c0..3eb9cfd 100644
--- a/spec/semantic_range_spec.rb
+++ b/spec/semantic_range_spec.rb
@@ -73,15 +73,6 @@
       expect(SemanticRange.cmp(v0, '>=', v1, loose: loose)).to eq(true)
       expect(SemanticRange.cmp(v1, '<=', v0, loose: loose)).to eq(true)
       expect(SemanticRange.cmp(v0, '!=', v1, loose: loose)).to eq(true)
-
-      # Backwards-compatibility
-      expect(SemanticRange.gt(v0, v1, loose: loose)).to eq(true)
-      expect(SemanticRange.lt(v1, v0, loose: loose)).to eq(true)
-      expect(SemanticRange.lt(v0, v1, loose: loose)).to eq(false)
-      expect(SemanticRange.gt(v1, v0, loose: loose)).to eq(false)
-      expect(SemanticRange.eq(v0, v0, loose: loose)).to eq(true)
-      expect(SemanticRange.eq(v1, v1, loose: loose)).to eq(true)
-      expect(SemanticRange.neq(v0, v1, loose: loose)).to eq(true)
     end
   end
 
@@ -138,14 +129,6 @@
       expect(SemanticRange.gte?(v0, v1, loose: loose)).to eq(true)
       expect(SemanticRange.lt?(v0, v1, loose: loose)).to eq(false)
       expect(SemanticRange.lte?(v0, v1, loose: loose)).to eq(true)
-
-      # Backwards-compatibility
-      expect(SemanticRange.eq(v0, v1, loose: loose)).to eq(true)
-      expect(SemanticRange.neq(v0, v1, loose: loose)).to eq(false)
-      expect(SemanticRange.gt(v0, v1, loose: loose)).to eq(false)
-      expect(SemanticRange.gte(v0, v1, loose: loose)).to eq(true)
-      expect(SemanticRange.lt(v0, v1, loose: loose)).to eq(false)
-      expect(SemanticRange.lte(v0, v1, loose: loose)).to eq(true)
     end
   end
 
@@ -155,9 +138,9 @@
       ['^1.2.3+build', '1.2.3'],
       ['^1.2.3+build', '1.3.0'],
       ['1.2.3-pre+asdf - 2.4.3-pre+asdf', '1.2.3'],
-      ['1.2.3pre+asdf - 2.4.3-pre+asdf', '1.2.3', true],
-      ['1.2.3-pre+asdf - 2.4.3pre+asdf', '1.2.3', true],
-      ['1.2.3pre+asdf - 2.4.3pre+asdf', '1.2.3', true],
+      ['1.2.3pre+asdf - 2.4.3-pre+asdf', '1.2.3', loose: true],
+      ['1.2.3-pre+asdf - 2.4.3pre+asdf', '1.2.3', loose: true],
+      ['1.2.3pre+asdf - 2.4.3pre+asdf', '1.2.3', loose: true],
       ['1.2.3-pre+asdf - 2.4.3-pre+asdf', '1.2.3-pre.2'],
       ['1.2.3-pre+asdf - 2.4.3-pre+asdf', '2.4.3-alpha'],
       ['1.2.3+asdf - 2.4.3+asdf', '1.2.3'],
@@ -165,10 +148,10 @@
       ['>=*', '0.2.4'],
       ['', '1.0.0'],
       ['*', '1.2.3'],
-      ['*', 'v1.2.3', true],
-      ['>=1.0.0', '1.0.0'],
-      ['>=1.0.0', '1.0.1'],
-      ['>=1.0.0', '1.1.0'],
+      ['*', 'v1.2.3', loose: 123],
+      ['>=1.0.0', '1.0.0', loose: /asdf/],
+      ['>=1.0.0', '1.0.1', loose: nil],
+      ['>=1.0.0', '1.1.0', loose: 0],
       ['>1.0.0', '1.0.1'],
       ['>1.0.0', '1.1.0'],
       ['<=2.0.0', '2.0.0'],
@@ -186,7 +169,7 @@
       ['<=  2.0.0', '0.2.9'],
       ['<    2.0.0', '1.9999.9999'],
       ["<\t2.0.0", '0.2.9'],
-      ['>=0.1.97', 'v0.1.97', true],
+      ['>=0.1.97', 'v0.1.97', loose: true],
       ['>=0.1.97', '0.1.97'],
       ['0.1.20 || 1.2.4', '1.2.4'],
       ['>=0.2.3 || <0.0.1', '0.0.0'],
@@ -205,6 +188,10 @@
       ['*', '1.2.3'],
       ['2', '2.1.2'],
       ['2.3', '2.3.1'],
+      ['~0.0.1', '0.0.1'],
+      ['~0.0.1', '0.0.2'],
+      ['~x', '0.0.9'], # >=2.4.0 <2.5.0
+      ['~2', '2.0.9'], # >=2.4.0 <2.5.0
       ['~2.4', '2.4.0'], # >=2.4.0 <2.5.0
       ['~2.4', '2.4.5'],
       ['~>3.2.1', '3.2.2'], # >=3.2.1 <3.3.0,
@@ -214,6 +201,7 @@
       ['~1.0', '1.0.2'], # >=1.0.0 <1.1.0,
       ['~ 1.0', '1.0.2'],
       ['~ 1.0.3', '1.0.12'],
+      ['~ 1.0.3alpha', '1.0.12', loose: true],
       ['>=1', '1.0.0'],
       ['>= 1', '1.0.0'],
       ['<1.2', '1.1.1'],
@@ -238,19 +226,43 @@
       ['^1.2.3', '1.8.1'],
       ['^0.1.2', '0.1.2'],
       ['^0.1', '0.1.2'],
+      ['^0.0.1', '0.0.1'],
       ['^1.2', '1.4.2'],
       ['^1.2 ^1', '1.4.2'],
       ['^1.2.3-alpha', '1.2.3-pre'],
       ['^1.2.0-alpha', '1.2.0-pre'],
-      ['^0.0.1-alpha', '0.0.1-beta']
+      ['^0.0.1-alpha', '0.0.1-beta'],
+      ['^0.0.1-alpha', '0.0.1'],
+      ['^0.1.1-alpha', '0.1.1-beta'],
+      ['^x', '1.2.3'],
+      ['x - 1.0.0', '0.9.7'],
+      ['x - 1.x', '0.9.7'],
+      ['1.0.0 - x', '1.9.7'],
+      ['1.x - x', '1.9.7'],
+      ['<=7.x', '7.9.9'],
+      ['2.x', '2.0.0-pre.0', include_prerelease: true],
+      ['2.x', '2.1.0-pre.0', include_prerelease: true],
+      ['1.1.x', '1.1.0-a', include_prerelease: true],
+      ['1.1.x', '1.1.1-a', include_prerelease: true],
+      ['*', '1.0.0-rc1', include_prerelease: true],
+      ['^1.0.0-0', '1.0.1-rc1', include_prerelease: true],
+      ['^1.0.0-rc2', '1.0.1-rc1', include_prerelease: true],
+      ['^1.0.0', '1.0.1-rc1', include_prerelease: true],
+      ['^1.0.0', '1.1.0-rc1', include_prerelease: true],
+      ['1 - 2', '2.0.0-pre', include_prerelease: true],
+      ['1 - 2', '1.0.0-pre', include_prerelease: true],
+      ['1.0 - 2', '1.0.0-pre', include_prerelease: true],
+
+      ['=0.7.x', '0.7.0-asdf', include_prerelease: true],
+      ['>=0.7.x', '0.7.0-asdf', include_prerelease: true],
+      ['<=0.7.x', '0.7.0-asdf', include_prerelease: true],
+
+      ['>=1.0.0 <=1.1.0', '1.1.0-pre', include_prerelease: true],
     ].each do |tuple|
       range = tuple[0]
       version = tuple[1]
-      loose = tuple[2]
-      expect(SemanticRange.satisfies?(version, range, loose: loose)).to eq(true), "#{tuple}"
-
-      # Backwards-compatibility
-      expect(SemanticRange.satisfies(version, range, loose: loose)).to eq(true), "#{tuple}"
+      options = tuple[2] || {}
+      expect(SemanticRange.satisfies?(version, range, **options)).to eq(true), "#{tuple}"
     end
   end
 
@@ -268,9 +280,10 @@
       ['^1.2.3', '1.2.3-beta'],
       ['=0.7.x', '0.7.0-asdf'],
       ['>=0.7.x', '0.7.0-asdf'],
-      ['1', '1.0.0beta', true],
-      ['<1', '1.0.0beta', true],
-      ['< 1', '1.0.0beta', true],
+      ['<=0.7.x', '0.7.0-asdf'],
+      ['1', '1.0.0beta', loose: 420],
+      ['<1', '1.0.0beta', loose: true],
+      ['< 1', '1.0.0beta', loose: true],
       ['1.0.0', '1.0.1'],
       ['>=1.0.0', '0.0.0'],
       ['>=1.0.0', '0.0.1'],
@@ -282,7 +295,7 @@
       ['<=2.0.0', '2.2.9'],
       ['<2.0.0', '2.9999.9999'],
       ['<2.0.0', '2.2.9'],
-      ['>=0.1.97', 'v0.1.93', true],
+      ['>=0.1.97', 'v0.1.93', loose: true],
       ['>=0.1.97', '0.1.93'],
       ['0.1.20 || 1.2.4', '1.2.3'],
       ['>=0.2.3 || <0.0.1', '0.0.3'],
@@ -299,6 +312,8 @@
       ['1.2.* || 2.*', '1.1.3'],
       ['2', '1.1.2'],
       ['2.3', '2.4.1'],
+      ['~0.0.1', '0.1.0-alpha'],
+      ['~0.0.1', '0.1.0'],
       ['~2.4', '2.5.0'], # >=2.4.0 <2.5.0
       ['~2.4', '2.3.9'],
       ['~>3.2.1', '3.3.2'], # >=3.2.1 <3.3.0
@@ -308,7 +323,7 @@
       ['~1.0', '1.1.0'], # >=1.0.0 <1.1.0
       ['<1', '1.0.0'],
       ['>=1.2', '1.1.1'],
-      ['1', '2.0.0beta', true],
+      ['1', '2.0.0beta', loose: true],
       ['~v0.5.4-beta', '0.5.4-alpha'],
       ['=0.7.x', '0.8.2'],
       ['>=0.7.x', '0.6.2'],
@@ -316,29 +331,61 @@
       ['<1.2.3', '1.2.3-beta'],
       ['=1.2.3', '1.2.3-beta'],
       ['>1.2', '1.2.8'],
+      ['^0.0.1', '0.0.2-alpha'],
+      ['^0.0.1', '0.0.2'],
       ['^1.2.3', '2.0.0-alpha'],
       ['^1.2.3', '1.2.2'],
       ['^1.2', '1.1.9'],
-      ['*', 'v1.2.3-foo', true],
-      # invalid ranges never satisfied!
-      ['blerg', '1.2.3'],
-      ['git+https:#user:password0123@github.com/foo', '123.0.0', true],
-      ['^1.2.3', '2.0.0-pre']
+      ['*', 'v1.2.3-foo', loose: true],
+
+      ['*', 'not a version'],
+      ['>=2', 'glorp'],
+      ['>=2', loose: false],
+
+      ['2.x', '3.0.0-pre.0', include_prerelease: true],
+      ['^1.0.0', '1.0.0-rc1', include_prerelease: true],
+      ['^1.0.0', '2.0.0-rc1', include_prerelease: true],
+      ['^1.2.3-rc2', '2.0.0', include_prerelease: true],
+      ['^1.0.0', '2.0.0-rc1', include_prerelease: true],
+      ['^1.0.0', '2.0.0-rc1'],
+
+      ['1 - 2', '3.0.0-pre', include_prerelease: true],
+      ['1 - 2', '2.0.0-pre'],
+      ['1 - 2', '1.0.0-pre'],
+      ['1.0 - 2', '1.0.0-pre'],
+
+      ['1.1.x', '1.0.0-a'],
+      ['1.1.x', '1.1.0-a'],
+      ['1.1.x', '1.2.0-a'],
+      ['1.1.x', '1.2.0-a', include_prerelease: true],
+      ['1.1.x', '1.0.0-a', include_prerelease: true],
+      ['1.x', '1.0.0-a'],
+      ['1.x', '1.1.0-a'],
+      ['1.x', '1.2.0-a'],
+      ['1.x', '0.0.0-a', include_prerelease: true],
+      ['1.x', '2.0.0-a', include_prerelease: true],
+
+      ['>=1.0.0 <1.1.0', '1.1.0'],
+      ['>=1.0.0 <1.1.0', '1.1.0', include_prerelease: true],
+      ['>=1.0.0 <1.1.0', '1.1.0-pre'],
+      ['>=1.0.0 <1.1.0-pre', '1.1.0-pre'],
     ].each do |tuple|
       range = tuple[0]
       version = tuple[1]
-      loose = tuple[2]
-      expect(SemanticRange.satisfies?(version, range, loose: loose)).to eq(false), "#{tuple}"
-
-      # Backwards-compatibility
-      expect(SemanticRange.satisfies(version, range, loose: loose)).to eq(false), "#{tuple}"
+      options = tuple[2] || {}
+      expect(SemanticRange.satisfies?(version, range, **options)).to eq(false), "#{tuple}"
     end
   end
 
   it 'valid range' do
     [
       ['1.0.0 - 2.0.0', '>=1.0.0 <=2.0.0'],
-      ['1.0.0', '1.0.0'],
+      ['1.0.0 - 2.0.0', '>=1.0.0-0 <2.0.1-0', include_prerelease: true],
+      ['1 - 2', '>=1.0.0 <3.0.0-0'],
+      ['1 - 2', '>=1.0.0-0 <3.0.0-0', include_prerelease: true],
+      ['1.0 - 2.0', '>=1.0.0 <2.1.0-0'],
+      ['1.0 - 2.0', '>=1.0.0-0 <2.1.0-0', include_prerelease: true],
+      ['1.0.0', '1.0.0', loose: false],
       ['>=*', '*'],
       ['', '*'],
       ['*', '*'],
@@ -346,7 +393,7 @@
       ['>=1.0.0', '>=1.0.0'],
       ['>1.0.0', '>1.0.0'],
       ['<=2.0.0', '<=2.0.0'],
-      ['1', '>=1.0.0 <2.0.0'],
+      ['1', '>=1.0.0 <2.0.0-0'],
       ['<=2.0.0', '<=2.0.0'],
       ['<=2.0.0', '<=2.0.0'],
       ['<2.0.0', '<2.0.0'],
@@ -360,60 +407,69 @@
       ['<= 2.0.0', '<=2.0.0'],
       ['<=  2.0.0', '<=2.0.0'],
       ['<    2.0.0', '<2.0.0'],
-      ['<	2.0.0', '<2.0.0'],
+      ["<\t2.0.0", '<2.0.0'],
       ['>=0.1.97', '>=0.1.97'],
       ['>=0.1.97', '>=0.1.97'],
       ['0.1.20 || 1.2.4', '0.1.20||1.2.4'],
       ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
       ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
       ['>=0.2.3 || <0.0.1', '>=0.2.3||<0.0.1'],
-      ['||', '||'],
-      ['2.x.x', '>=2.0.0 <3.0.0'],
-      ['1.2.x', '>=1.2.0 <1.3.0'],
-      ['1.2.x || 2.x', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
-      ['1.2.x || 2.x', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
+      ['||', '*'],
+      ['2.x.x', '>=2.0.0 <3.0.0-0'],
+      ['1.2.x', '>=1.2.0 <1.3.0-0'],
+      ['1.2.x || 2.x', '>=1.2.0 <1.3.0-0||>=2.0.0 <3.0.0-0'],
+      ['1.2.x || 2.x', '>=1.2.0 <1.3.0-0||>=2.0.0 <3.0.0-0'],
       ['x', '*'],
-      ['2.*.*', '>=2.0.0 <3.0.0'],
-      ['1.2.*', '>=1.2.0 <1.3.0'],
-      ['1.2.* || 2.*', '>=1.2.0 <1.3.0||>=2.0.0 <3.0.0'],
+      ['2.*.*', '>=2.0.0 <3.0.0-0'],
+      ['1.2.*', '>=1.2.0 <1.3.0-0'],
+      ['1.2.* || 2.*', '>=1.2.0 <1.3.0-0||>=2.0.0 <3.0.0-0'],
       ['*', '*'],
-      ['2', '>=2.0.0 <3.0.0'],
-      ['2.3', '>=2.3.0 <2.4.0'],
-      ['~2.4', '>=2.4.0 <2.5.0'],
-      ['~2.4', '>=2.4.0 <2.5.0'],
-      ['~>3.2.1', '>=3.2.1 <3.3.0'],
-      ['~1', '>=1.0.0 <2.0.0'],
-      ['~>1', '>=1.0.0 <2.0.0'],
-      ['~> 1', '>=1.0.0 <2.0.0'],
-      ['~1.0', '>=1.0.0 <1.1.0'],
-      ['~ 1.0', '>=1.0.0 <1.1.0'],
-      ['^0', '>=0.0.0 <1.0.0'],
-      ['^ 1', '>=1.0.0 <2.0.0'],
-      ['^0.1', '>=0.1.0 <0.2.0'],
-      ['^1.0', '>=1.0.0 <2.0.0'],
-      ['^1.2', '>=1.2.0 <2.0.0'],
-      ['^0.0.1', '>=0.0.1 <0.0.2'],
-      ['^0.0.1-beta', '>=0.0.1-beta <0.0.2'],
-      ['^0.1.2', '>=0.1.2 <0.2.0'],
-      ['^1.2.3', '>=1.2.3 <2.0.0'],
-      ['^1.2.3-beta.4', '>=1.2.3-beta.4 <2.0.0'],
-      ['<1', '<1.0.0'],
-      ['< 1', '<1.0.0'],
+      ['2', '>=2.0.0 <3.0.0-0'],
+      ['2.3', '>=2.3.0 <2.4.0-0'],
+      ['~2.4', '>=2.4.0 <2.5.0-0'],
+      ['~2.4', '>=2.4.0 <2.5.0-0'],
+      ['~>3.2.1', '>=3.2.1 <3.3.0-0'],
+      ['~1', '>=1.0.0 <2.0.0-0'],
+      ['~>1', '>=1.0.0 <2.0.0-0'],
+      ['~> 1', '>=1.0.0 <2.0.0-0'],
+      ['~1.0', '>=1.0.0 <1.1.0-0'],
+      ['~ 1.0', '>=1.0.0 <1.1.0-0'],
+      ['^0', '<1.0.0-0'],
+      ['^ 1', '>=1.0.0 <2.0.0-0'],
+      ['^0.1', '>=0.1.0 <0.2.0-0'],
+      ['^1.0', '>=1.0.0 <2.0.0-0'],
+      ['^1.2', '>=1.2.0 <2.0.0-0'],
+      ['^0.0.1', '>=0.0.1 <0.0.2-0'],
+      ['^0.0.1-beta', '>=0.0.1-beta <0.0.2-0'],
+      ['^0.1.2', '>=0.1.2 <0.2.0-0'],
+      ['^1.2.3', '>=1.2.3 <2.0.0-0'],
+      ['^1.2.3-beta.4', '>=1.2.3-beta.4 <2.0.0-0'],
+      ['<1', '<1.0.0-0'],
+      ['< 1', '<1.0.0-0'],
       ['>=1', '>=1.0.0'],
       ['>= 1', '>=1.0.0'],
-      ['<1.2', '<1.2.0'],
-      ['< 1.2', '<1.2.0'],
-      ['1', '>=1.0.0 <2.0.0'],
-      ['>01.02.03', '>1.2.3', true],
+      ['<1.2', '<1.2.0-0'],
+      ['< 1.2', '<1.2.0-0'],
+      ['1', '>=1.0.0 <2.0.0-0'],
+      ['>01.02.03', '>1.2.3', loose: true],
       ['>01.02.03', nil],
-      ['~1.2.3beta', '>=1.2.3-beta <1.3.0', true],
+      ['~1.2.3beta', '>=1.2.3-beta <1.3.0-0', loose: true],
       ['~1.2.3beta', nil],
-      ['^ 1.2 ^ 1', '>=1.2.0 <2.0.0 >=1.0.0 <2.0.0']
+      ['^ 1.2 ^ 1', '>=1.2.0 <2.0.0-0 >=1.0.0'],
+      ['1.2 - 3.4.5', '>=1.2.0 <=3.4.5'],
+      ['1.2.3 - 3.4', '>=1.2.3 <3.5.0-0'],
+      ['1.2 - 3.4', '>=1.2.0 <3.5.0-0'],
+      ['>1', '>=2.0.0'],
+      ['>1.2', '>=1.3.0'],
+      ['>X', '<0.0.0-0'],
+      ['<X', '<0.0.0-0'],
+      ['<x <* || >* 2.x', '<0.0.0-0'],
+      ['>x 2.x || * || <x', '*'],
     ].each do |tuple|
       pre = tuple[0]
       wanted = tuple[1]
-      loose = tuple[2]
-      expect(SemanticRange.valid_range(pre, loose: loose)).to eq(wanted)
+      options = tuple[2] || {}
+      expect(SemanticRange.valid_range(pre, **options)).to eq(wanted)
     end
   end
 
@@ -425,15 +481,6 @@
     expect(SemanticRange.lt?('2.2.4', '2.2.2', loose: false)).to eq(false)
     expect(SemanticRange.lt?('2.2.4', '1.2.2', loose: false)).to eq(false)
     expect(SemanticRange.lt?('2.2.4', '2.1.2', loose: false)).to eq(false)
-
-    # Backwards-compatibility
-    expect(SemanticRange.lt('1.2.4', '1.3.0', loose: false)).to eq(true)
-    expect(SemanticRange.lt('1.2.4', '1.2.5', loose: false)).to eq(true)
-    expect(SemanticRange.lt('1.2.4', '2.2.5', loose: false)).to eq(true)
-
-    expect(SemanticRange.lt('2.2.4', '2.2.2', loose: false)).to eq(false)
-    expect(SemanticRange.lt('2.2.4', '1.2.2', loose: false)).to eq(false)
-    expect(SemanticRange.lt('2.2.4', '2.1.2', loose: false)).to eq(false)
   end
 
   it 'gt?' do
@@ -449,42 +496,18 @@
     expect(SemanticRange.gt?('1.4.0', SemanticRange::Version.new('1.4.0'))).to eq(false)
     expect(SemanticRange.gt?(SemanticRange::Version.new('1.4.0'), '1.4.0')).to eq(false)
     expect(SemanticRange.gt?(SemanticRange::Version.new('1.4.0'), SemanticRange::Version.new('1.4.0'))).to eq(false)
-
-    # Backwards-compatibility
-    expect(SemanticRange.gt('1.2.4', '1.3.0')).to eq(false)
-    expect(SemanticRange.gt('1.2.4', '1.2.5')).to eq(false)
-    expect(SemanticRange.gt('1.2.4', '2.2.5')).to eq(false)
-
-    expect(SemanticRange.gt('2.2.4', '2.2.2')).to eq(true)
-    expect(SemanticRange.gt('2.2.4', '1.2.2')).to eq(true)
-    expect(SemanticRange.gt('2.2.4', '2.1.2')).to eq(true)
-
-    expect(SemanticRange.gt('1.4.0', '1.4.0')).to eq(false)
-    expect(SemanticRange.gt('1.4.0', SemanticRange::Version.new('1.4.0'))).to eq(false)
-    expect(SemanticRange.gt(SemanticRange::Version.new('1.4.0'), '1.4.0')).to eq(false)
-    expect(SemanticRange.gt(SemanticRange::Version.new('1.4.0'), SemanticRange::Version.new('1.4.0'))).to eq(false)
-end
+  end
 
   it 'eq?' do
     expect(SemanticRange.eq?('1.2.4', '1.1.0')).to eq(false)
     expect(SemanticRange.eq?('1.2.4', '1.2.4')).to eq(true)
     expect(SemanticRange.eq?('1.2.4', '2.2.5')).to eq(false)
-
-    # Backwards-compatibility
-    expect(SemanticRange.eq('1.2.4', '1.1.0')).to eq(false)
-    expect(SemanticRange.eq('1.2.4', '1.2.4')).to eq(true)
-    expect(SemanticRange.eq('1.2.4', '2.2.5')).to eq(false)
   end
 
   it 'neq?' do
     expect(SemanticRange.neq?('1.2.4', '1.1.0')).to eq(true)
     expect(SemanticRange.neq?('1.2.4', '1.2.4')).to eq(false)
     expect(SemanticRange.neq?('1.2.4', '2.2.5')).to eq(true)
-
-    # Backwards-compatibility
-    expect(SemanticRange.neq('1.2.4', '1.1.0')).to eq(true)
-    expect(SemanticRange.neq('1.2.4', '1.2.4')).to eq(false)
-    expect(SemanticRange.neq('1.2.4', '2.2.5')).to eq(true)
   end
 
   it 'lte?' do
@@ -496,16 +519,6 @@
     expect(SemanticRange.lte?('2.2.4', '2.2.2')).to eq(false)
     expect(SemanticRange.lte?('2.2.4', '1.2.2')).to eq(false)
     expect(SemanticRange.lte?('2.2.4', '2.1.2')).to eq(false)
-
-    # Backwards-compatibility
-    expect(SemanticRange.lte('1.2.4', '1.3.0')).to eq(true)
-    expect(SemanticRange.lte('1.2.4', '1.2.5')).to eq(true)
-    expect(SemanticRange.lte('1.2.4', '2.2.5')).to eq(true)
-    expect(SemanticRange.lte('1.2.4', '1.2.4')).to eq(true)
-
-    expect(SemanticRange.lte('2.2.4', '2.2.2')).to eq(false)
-    expect(SemanticRange.lte('2.2.4', '1.2.2')).to eq(false)
-    expect(SemanticRange.lte('2.2.4', '2.1.2')).to eq(false)
   end
 
   it 'gte?' do
@@ -517,16 +530,6 @@
     expect(SemanticRange.gte?('2.2.4', '2.2.2')).to eq(true)
     expect(SemanticRange.gte?('2.2.4', '1.2.2')).to eq(true)
     expect(SemanticRange.gte?('2.2.4', '2.1.2')).to eq(true)
-
-    # Backwards-compatibility
-    expect(SemanticRange.gte('1.2.4', '1.3.0')).to eq(false)
-    expect(SemanticRange.gte('1.2.4', '1.2.5')).to eq(false)
-    expect(SemanticRange.gte('1.2.4', '2.2.5')).to eq(false)
-
-    expect(SemanticRange.lte('1.2.4', '1.2.4')).to eq(true)
-    expect(SemanticRange.gte('2.2.4', '2.2.2')).to eq(true)
-    expect(SemanticRange.gte('2.2.4', '1.2.2')).to eq(true)
-    expect(SemanticRange.gte('2.2.4', '2.1.2')).to eq(true)
   end
 
   it 'diff versions' do
@@ -575,17 +578,13 @@
       expect(SemanticRange.eq?(loose, strict, loose: true)).to eq(true)
       expect { SemanticRange.eq?(loose, strict) }.to raise_error(SemanticRange::InvalidVersion)
       expect { SemanticRange::Version.new(strict).compare(loose) }.to raise_error(SemanticRange::InvalidVersion)
-
-      # Backwards-compatibility
-      expect(SemanticRange.eq(loose, strict, loose: true)).to eq(true)
-      expect { SemanticRange.eq(loose, strict) }.to raise_error(SemanticRange::InvalidVersion)
     end
   end
 
   it 'strict vs loose ranges' do
     [
       ['>=01.02.03', '>=1.2.3'],
-      ['~1.02.03beta', '>=1.2.3-beta <1.3.0']
+      ['~1.02.03beta', '>=1.2.3-beta <1.3.0-0']
     ].each do |v|
       loose, comps = v
       expect { SemanticRange::Range.new(loose) }.to raise_error(SemanticRange::InvalidRange)
@@ -614,17 +613,10 @@
       ['>=*', [['']]],
       ['', [['']]],
       ['*', [['']]],
-      ['*', [['']]],
-      ['>=1.0.0', [['>=1.0.0']]],
       ['>=1.0.0', [['>=1.0.0']]],
-      ['>=1.0.0', [['>=1.0.0']]],
-      ['>1.0.0', [['>1.0.0']]],
       ['>1.0.0', [['>1.0.0']]],
       ['<=2.0.0', [['<=2.0.0']]],
-      ['1', [['>=1.0.0', '<2.0.0']]],
-      ['<=2.0.0', [['<=2.0.0']]],
-      ['<=2.0.0', [['<=2.0.0']]],
-      ['<2.0.0', [['<2.0.0']]],
+      ['1', [['>=1.0.0', '<2.0.0-0']]],
       ['<2.0.0', [['<2.0.0']]],
       ['>= 1.0.0', [['>=1.0.0']]],
       ['>=  1.0.0', [['>=1.0.0']]],
@@ -637,47 +629,43 @@
       ['<    2.0.0', [['<2.0.0']]],
       ["<\t2.0.0", [['<2.0.0']]],
       ['>=0.1.97', [['>=0.1.97']]],
-      ['>=0.1.97', [['>=0.1.97']]],
       ['0.1.20 || 1.2.4', [['0.1.20'], ['1.2.4']]],
       ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['>=0.2.3 || <0.0.1', [['>=0.2.3'], ['<0.0.1']]],
-      ['||', [[''], ['']]],
-      ['2.x.x', [['>=2.0.0', '<3.0.0']]],
-      ['1.2.x', [['>=1.2.0', '<1.3.0']]],
-      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
+      ['||', [['']]],
+      ['2.x.x', [['>=2.0.0', '<3.0.0-0']]],
+      ['1.2.x', [['>=1.2.0', '<1.3.0-0']]],
+      ['1.2.x || 2.x', [['>=1.2.0', '<1.3.0-0'], ['>=2.0.0', '<3.0.0-0']]],
       ['x', [['']]],
-      ['2.*.*', [['>=2.0.0', '<3.0.0']]],
-      ['1.2.*', [['>=1.2.0', '<1.3.0']]],
-      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0'], ['>=2.0.0', '<3.0.0']]],
-      ['*', [['']]],
-      ['2', [['>=2.0.0', '<3.0.0']]],
-      ['2.3', [['>=2.3.0', '<2.4.0']]],
-      ['~2.4', [['>=2.4.0', '<2.5.0']]],
-      ['~2.4', [['>=2.4.0', '<2.5.0']]],
-      ['~>3.2.1', [['>=3.2.1', '<3.3.0']]],
-      ['~1', [['>=1.0.0', '<2.0.0']]],
-      ['~>1', [['>=1.0.0', '<2.0.0']]],
-      ['~> 1', [['>=1.0.0', '<2.0.0']]],
-      ['~1.0', [['>=1.0.0', '<1.1.0']]],
-      ['~ 1.0', [['>=1.0.0', '<1.1.0']]],
-      ['~ 1.0.3', [['>=1.0.3', '<1.1.0']]],
-      ['~> 1.0.3', [['>=1.0.3', '<1.1.0']]],
-      ['<1', [['<1.0.0']]],
-      ['< 1', [['<1.0.0']]],
+      ['2.*.*', [['>=2.0.0', '<3.0.0-0']]],
+      ['1.2.*', [['>=1.2.0', '<1.3.0-0']]],
+      ['1.2.* || 2.*', [['>=1.2.0', '<1.3.0-0'], ['>=2.0.0', '<3.0.0-0']]],
+      ['2', [['>=2.0.0', '<3.0.0-0']]],
+      ['2.3', [['>=2.3.0', '<2.4.0-0']]],
+      ['~2.4', [['>=2.4.0', '<2.5.0-0']]],
+      ['~>3.2.1', [['>=3.2.1', '<3.3.0-0']]],
+      ['~1', [['>=1.0.0', '<2.0.0-0']]],
+      ['~>1', [['>=1.0.0', '<2.0.0-0']]],
+      ['~> 1', [['>=1.0.0', '<2.0.0-0']]],
+      ['~1.0', [['>=1.0.0', '<1.1.0-0']]],
+      ['~ 1.0', [['>=1.0.0', '<1.1.0-0']]],
+      ['~ 1.0.3', [['>=1.0.3', '<1.1.0-0']]],
+      ['~> 1.0.3', [['>=1.0.3', '<1.1.0-0']]],
+      ['<1', [['<1.0.0-0']]],
+      ['< 1', [['<1.0.0-0']]],
       ['>=1', [['>=1.0.0']]],
       ['>= 1', [['>=1.0.0']]],
-      ['<1.2', [['<1.2.0']]],
-      ['< 1.2', [['<1.2.0']]],
-      ['1', [['>=1.0.0', '<2.0.0']]],
-      ['1 2', [['>=1.0.0', '<2.0.0', '>=2.0.0', '<3.0.0']]],
+      ['<1.2', [['<1.2.0-0']]],
+      ['< 1.2', [['<1.2.0-0']]],
+      ['1 2', [['>=1.0.0', '<2.0.0-0', '>=2.0.0', '<3.0.0-0']]],
       ['1.2 - 3.4.5', [['>=1.2.0', '<=3.4.5']]],
-      ['1.2.3 - 3.4', [['>=1.2.3', '<3.5.0']]],
-      ['1.2.3 - 3', [['>=1.2.3', '<4.0.0']]],
-      ['>*', [['<0.0.0']]],
-      ['<*', [['<0.0.0']]]
+      ['1.2.3 - 3.4', [['>=1.2.3', '<3.5.0-0']]],
+      ['1.2.3 - 3', [['>=1.2.3', '<4.0.0-0']]],
+      ['>*', [['<0.0.0-0']]],
+      ['<*', [['<0.0.0-0']]],
+      ['>X', [['<0.0.0-0']]],
+      ['<X', [['<0.0.0-0']]],
+      ['<x <* || >* 2.x', [['<0.0.0-0']]],
+      ['>x 2.x || * || <x', [['']]],
     ].each do |v|
       pre, wanted = v
       found = SemanticRange.to_comparators(pre)
@@ -701,71 +689,64 @@
 
   it 'intersect comparators' do
     [
-        # One is a Version
-        ['1.3.0', '>=1.3.0', true],
-        ['1.3.0', '>1.3.0', false],
-        ['>=1.3.0', '1.3.0', true],
-        ['>1.3.0', '1.3.0', false],
-        # Same direction increasing
-        ['>1.3.0', '>1.2.0', true],
-        ['>1.2.0', '>1.3.0', true],
-        ['>=1.2.0', '>1.3.0', true],
-        ['>1.2.0', '>=1.3.0', true],
-        # Same direction decreasing
-        ['<1.3.0', '<1.2.0', true],
-        ['<1.2.0', '<1.3.0', true],
-        ['<=1.2.0', '<1.3.0', true],
-        ['<1.2.0', '<=1.3.0', true],
-        # Different directions, same semver and inclusive operator
-        ['>=1.3.0', '<=1.3.0', true],
-        ['>=1.3.0', '>=1.3.0', true],
-        ['<=1.3.0', '<=1.3.0', true],
-        ['>1.3.0', '<=1.3.0', false],
-        ['>=1.3.0', '<1.3.0', false],
-        # Opposite matching directions
-        ['>1.0.0', '<2.0.0', true],
-        ['>=1.0.0', '<2.0.0', true],
-        ['>=1.0.0', '<=2.0.0', true],
-        ['>1.0.0', '<=2.0.0', true],
-        ['<=2.0.0', '>1.0.0', true],
-        ['<=1.0.0', '>=2.0.0', false]
+      # One is a Version
+      ['1.3.0', '>=1.3.0', true],
+      ['1.3.0', '>1.3.0', false],
+      ['>=1.3.0', '1.3.0', true],
+      ['>1.3.0', '1.3.0', false],
+      # Same direction increasing
+      ['>1.3.0', '>1.2.0', true],
+      ['>1.2.0', '>1.3.0', true],
+      ['>=1.2.0', '>1.3.0', true],
+      ['>1.2.0', '>=1.3.0', true],
+      # Same direction decreasing
+      ['<1.3.0', '<1.2.0', true],
+      ['<1.2.0', '<1.3.0', true],
+      ['<=1.2.0', '<1.3.0', true],
+      ['<1.2.0', '<=1.3.0', true],
+      # Different directions, same semver and inclusive operator
+      ['>=1.3.0', '<=1.3.0', true],
+      ['>=1.3.0', '>=1.3.0', true],
+      ['<=1.3.0', '<=1.3.0', true],
+      ['>1.3.0', '<=1.3.0', false],
+      ['>=1.3.0', '<1.3.0', false],
+      # Opposite matching directions
+      ['>1.0.0', '<2.0.0', true],
+      ['>=1.0.0', '<2.0.0', true],
+      ['>=1.0.0', '<=2.0.0', true],
+      ['>1.0.0', '<=2.0.0', true],
+      ['<=2.0.0', '>1.0.0', true],
+      ['<=1.0.0', '>=2.0.0', false]
     ].each do |c|
       comp_1 = SemanticRange::Comparator.new(c[0], nil)
       comp_2 = SemanticRange::Comparator.new(c[1], nil)
       expect(comp_1.intersects(comp_2)).to eq(c[2])
       expect(comp_2.intersects(comp_1)).to eq(c[2])
-
-      # Backwards-compatibility
-      expect(comp_1.intersects(comp_2)).to eq(c[2])
-      expect(comp_2.intersects(comp_1)).to eq(c[2])
     end
   end
 
   it 'comparator satisfies range' do
     [
-        ['1.3.0', '1.3.0 || <1.0.0 >2.0.0', true],
-        ['1.3.0', '<1.0.0 >2.0.0', false],
-        ['>=1.3.0', '<1.3.0', false],
-        ['<1.3.0', '>=1.3.0', false]
+      ['1.3.0', '1.3.0 || <1.0.0 >2.0.0', true],
+      ['1.3.0', '<1.0.0 >2.0.0', false],
+      ['>=1.3.0', '<1.3.0', false],
+      ['<1.3.0', '>=1.3.0', false]
     ].each do |c|
       comp = SemanticRange::Comparator.new(c[0], nil)
       range = SemanticRange::Range.new(c[1])
       expect(comp.satisfies_range?(range)).to eq(c[2])
-
-      # Backwards-compatibility
-      expect(comp.satisfies_range(range)).to eq(c[2])
     end
   end
 
   it 'ranges intersect' do
     [
-        ['1.3.0 || <1.0.0 >2.0.0', '1.3.0 || <1.0.0 >2.0.0', true],
-        ['<1.0.0 >2.0.0', '>0.0.0', true],
-        ['<1.0.0 >2.0.0', '>1.4.0 <1.6.0', false],
-        ['<1.0.0 >2.0.0', '>1.4.0 <1.6.0 || 2.0.0', false],
-        ['>1.0.0 <=2.0.0', '2.0.0', true],
-        ['<1.0.0 >=2.0.0', '2.1.0', false],
-        ['<1.0.0 >=2.0.0', '>1.4.0 <1.6.0 || 2.0.0', false]
+      ['1.3.0 || <1.0.0 >2.0.0', '1.3.0 || <1.0.0 >2.0.0', true],
+      ['<1.0.0 >2.0.0', '>0.0.0', true],
+      ['<1.0.0 >2.0.0', '>1.4.0 <1.6.0', false],
+      ['<1.0.0 >2.0.0', '>1.4.0 <1.6.0 || 2.0.0', false],
+      ['>1.0.0 <=2.0.0', '2.0.0', true],
+      ['<1.0.0 >=2.0.0', '2.1.0', false],
+      ['<1.0.0 >=2.0.0', '>1.4.0 <1.6.0 || 2.0.0', false]
     ].each do |c|
       range_1 = SemanticRange::Range.new(c[0])
       range_2 = SemanticRange::Range.new(c[1])
@@ -776,11 +757,11 @@
 
   it 'filters an array of versions that satisfy a range' do
     [
-        ['1.3.0 || <1.0.0 || >2.0.0', ['0.9.0', '1.3.0', '1.5.0', '2.0.5'], ['0.9.0', '1.3.0', '2.0.5']],
-        ['1.0.0 - 1.2.0', ['0.1.0', '1.0.1', '1.1.1', '1.2.0', '1.2.1'], ['1.0.1', '1.1.1', '1.2.0']],
-        ['^0.5.0', ['0.5.1', '0.6.0'], ['0.5.1']],
-        ['1.3.0', ['1.3.0', '2.0.0'], ['1.3.0']],
-        ['>=1.3.0', ['1.0.0', '1.3.0', '2.0.0'], ['1.3.0', '2.0.0']]
+      ['1.3.0 || <1.0.0 || >2.0.0', ['0.9.0', '1.3.0', '1.5.0', '2.0.5'], ['0.9.0', '1.3.0', '2.0.5']],
+      ['1.0.0 - 1.2.0', ['0.1.0', '1.0.1', '1.1.1', '1.2.0', '1.2.1'], ['1.0.1', '1.1.1', '1.2.0']],
+      ['^0.5.0', ['0.5.1', '0.6.0'], ['0.5.1']],
+      ['1.3.0', ['1.3.0', '2.0.0'], ['1.3.0']],
+      ['>=1.3.0', ['1.0.0', '1.3.0', '2.0.0'], ['1.3.0', '2.0.0']]
     ].each do |range, versions, expected|
       expect(SemanticRange.filter(versions, range)).to eq(expected)
     end