More tests

051-remove-vowels.dfy

@@ -1,4 +1,3 @@
-
 method remove_vowels(text : string) returns (s : string) 
     ensures forall i : int :: i >= 0 && i < |s| ==> s[i] != 'a' && s[i] != 'e' && s[i] != 'i' && s[i] != 'o' && s[i] != 'u'
     ensures forall i : int :: i >= 0 && i < |s| ==> s[i] in text

052-below_treshold.dfy

@@ -0,0 +1,16 @@
+method belowThreshold(l: seq<int>, t: int) returns (result: bool)
+  ensures result <==> forall i :: 0 <= i < |l| ==> l[i] < t
+{
+  result := true;
+  var i := 0;
+  while i < |l|
+    invariant 0 <= i <= |l|
+    invariant result <==> forall j :: 0 <= j < i ==> l[j] < t
+  {
+    if l[i] >= t {
+      result := false;
+      return;
+    }
+    i := i + 1;
+  }
+}

092-any_int.dfy

@@ -0,0 +1,5 @@
+method any_int(a: int, b: int, c: int) returns (r: bool)
+  ensures r == (a == b + c || b == a + c || c == a + b)
+{
+  r := a == b + c || b == a + c || c == a + b;
+}

095-check_dict_case.dfy

@@ -0,0 +1,44 @@
+predicate IsLowerCase(s: string)
+{
+  forall i :: 0 <= i < |s| ==> 'a' <= s[i] <= 'z'
+}
+
+predicate IsUpperCase(s: string)
+{
+  forall i :: 0 <= i < |s| ==> 'A' <= s[i] <= 'Z'
+}
+
+method CheckDictCase(dict: map<string, string>) returns (result: bool)
+  ensures dict == map[] ==> !result
+  ensures result ==> (forall k :: k in dict ==> IsLowerCase(k)) || (forall k :: k in dict ==> IsUpperCase(k))
+  ensures !result ==> dict == map[] || ((exists k :: k in dict && !IsLowerCase(k)) && (exists k :: k in dict && !IsUpperCase(k)))
+{
+  if |dict| == 0 {
+    return false;
+  }
+
+  var allLower := true;
+  var allUpper := true;
+
+  var keys := dict.Keys;
+  while keys != {}
+    invariant allLower ==> forall j :: j in dict.Keys - keys ==> IsLowerCase(j)
+    invariant allUpper ==> forall j :: j in dict.Keys - keys ==> IsUpperCase(j)
+    invariant !allLower ==> exists j :: j in dict.Keys - keys && !IsLowerCase(j)
+    invariant !allUpper ==> exists j :: j in dict.Keys - keys && !IsUpperCase(j)
+  {
+    var k :| k in keys;
+    if !IsLowerCase(k) {
+      allLower := false;
+    }
+    if !IsUpperCase(k) {
+      allUpper := false;
+    }
+    if !allLower && !allUpper {
+      return false;
+    }
+    keys := keys - {k};
+  }
+
+  result := allLower || allUpper;
+}

152-compare.dfy

@@ -0,0 +1,27 @@
+method Compare(scores: array<int>, guesses: array<int>) returns (result: array<int>)
+  requires scores.Length == guesses.Length
+  ensures result.Length == scores.Length
+  ensures forall i :: 0 <= i < result.Length ==> 
+    result[i] == if scores[i] == guesses[i] then 0 else abs(scores[i] - guesses[i])
+{
+  result := new int[scores.Length];
+  var i := 0;
+  while i < scores.Length
+    invariant 0 <= i <= scores.Length
+    invariant result.Length == scores.Length
+    invariant forall k :: 0 <= k < i ==> 
+      result[k] == if scores[k] == guesses[k] then 0 else abs(scores[k] - guesses[k])
+  {
+    if scores[i] == guesses[i] {
+      result[i] := 0;
+    } else {
+      result[i] := abs(scores[i] - guesses[i]);
+    }
+    i := i + 1;
+  }
+}
+
+function abs(x: int): int
+{
+  if x < 0 then -x else x
+}