Touch up the transpose show rule

README.md

@@ -17,7 +17,7 @@ This [Typst](https://typst.app) package provides handy typesetting utilities for
 natural sciences, including:
 * Braces,
 * Vectors and vector fields,
-* Matrices, including Jacobian and Hessian, interpreting `..^T` as transpose,
+* Matrices, including Jacobian and Hessian, smartly interpreting `..^T` as transpose,
 * Dirac braket notations,
 * Common math functions,
 * Differentials and derivatives, including partial derivatives of mixed orders with automatic order summation,

physica-manual.typ

@@ -785,36 +785,61 @@ In the default font, the Typst built-in symbol `planck.reduce` $planck.reduce$ l
   [$ i hbar pdv(,t) psi = -frac(hbar^2, 2m) laplacian psi $],
 )
 
-=== Matrix transpose <matrix-tranpose>
+=== Matrix transpose with superscript T <matrix-tranpose>
 
 #v(1em)
 
-Matrix transposition can be simply written as `..^T`, where the `T` will be
-formatted properly to represent transposition instead of a normal letter $T$.
-This conversion is disabled if the base is integral symbol.
+Matrix transposition can be simply written as `..^T`, just like handwriting,
+and the only superscript `T` will be formatted properly to represent
+transposition instead of a normal capital letter $T$.
 
-To enable this feature, users need to first import this and call
+This conversion is disabled if the base is either
+- a `limits(...)` or `scripts(...)` element, or
+- an integration symbol $integral$ or vertical bar $|$, or
+- an equation or `lr(...)` element whose last child is one of the above.
+
+If you really want to:
+- print a transpose explicitly: use symbol `TT`: `A^TT` $=> A^TT$;
+- print a superscript letter $T$: use `scripts(T)`: `2^scripts(T)` $=> 2^scripts(T)$.
+
+This feature needs to be enabled explicitly through a _show rule_.
 ```typ
-#import "...(this physica package)...": super-T-as-transpose
 #show: super-T-as-transpose
+(A B)^T = B^T A^T
+```
+
+If you only want to enable it within a content block's scope, you may do
+```typ
+#[
+  #show: super-T-as-transpose // Enabled from here till the end of block.
+  (A B)^T = B^T A^T
+]
 ```
 
 #align(center, [*Examples*])
 
 #show: super-T-as-transpose  // Necessary!
 
 #grid(
-  columns: (50%, 50%),
+  columns: (auto, auto),
   row-gutter: 1em,
   column-gutter: 2em,
 
   [
-    *(1)* #hl(`(A_n B_n)^T = B_n^T A_n^T`) \
-    $ (A_n B_n)^T = B_n^T A_n^T $
+    *(1)* #hl(`(U V_n W')^T = W'^T V_n^T U^T`) \
+    $ (U V_n W')^T = W'^T V_n^T U^T  $
+  ],
+  [
+    *(2)* #hl(`vec(a, b)^T, mat(a, b; c, d)^T`) \
+    $ vec(a, b)^T, mat(a, b; c, d)^T $
+  ],
+  [
+    *(3)* #hl(`limits(sum)^T, scripts(e)^T`) \
+    $ limits(sum)^T, scripts(e)^T $
   ],
   [
-    *(2)* #hl(`integral_0^T A^T f(x) dif x`) \
-    $ integral_0^T A^T f(x) dif x $
+    *(4)* #hl(`integral_0^T, abs(a)^T, eval(F(t))^T_0`) \
+    $ integral_0^T, abs(a)^T, eval(F(t))^T_0 $
   ],
 )
 

physica.typ

@@ -151,7 +151,11 @@
 
 #let vecrow(..content) = $lr(( #content.pos().join([,]) ))$
 
-// Prefer using super-T-as-transpose()
+// Prefer using super-T-as-transpose() found below.
+//
+// Note Unicode U+1D40 (#str.from-unicode(7488)) is kinda ugly, and that
+// glyph is in the superscript position already so users could not write
+// the habitual "A^TT".
 #let TT = $sans(upright(T))$
 
 #let __vector(a, accent, be_bold) = {
@@ -635,9 +639,29 @@
 // Credit: Enivex in https://github.com/typst/typst/issues/355 was very helpful.
 #let hbar = (sym.wj, move(dy: -0.08em, strike(offset: -0.55em, extent: -0.05em, sym.planck)), sym.wj).join()
 
+// A show rule, should be called like:
+//   #show: super-T-as-transpose
+//   (A B)^T = B^T A^T
+// or in scope:
+//   #[
+//     #show: super-T-as-transpose
+//     (A B)^T = B^T A^T
+//   ]
 #let super-T-as-transpose(document) = {
   show math.attach: elem => {
-    if elem.base != [∫] and elem.at("t", default: none) == [T] {
+    let __eligible(e) = {
+      if e.func() == math.limits or e.func() == math.scripts { return false }
+      if e.func() == math.lr {
+        let last = e.at("body").at("children").at(-1)
+        return __eligible(last)
+      }
+      if e.func() == math.equation {
+        return __eligible(e.at("body"))
+      }
+      (e != [∫]) and (e != [|]) and (e != sym.bar.v.double)
+    }
+
+    if __eligible(elem.base) and elem.at("t", default: none) == [T] {
       $attach(elem.base, t: TT, b: elem.at("b", default: #none))$
     } else {
       elem