fix #156

Author: arnog

CHANGELOG.md

@@ -212,6 +212,16 @@
   lower precedence (230-235) than comparison operators (245) and set relations
   (240), so compound propositions parse correctly without requiring parentheses.
 
+- **([#156](https://github.com/cortex-js/compute-engine/issues/156)) Logical
+  Connective Arrows**: Added support for lowercase arrow notation in logical
+  expressions:
+  - `\rightarrow` now parses as `Implies` (previously parsed as `To` for
+    set/function mapping)
+  - `\leftrightarrow` now parses as `Equivalent` (previously produced an
+    "unexpected-command" error)
+  - The uppercase variants `\Rightarrow` and `\Leftrightarrow` continue to work
+  - `\to` remains available for function/set mapping notation (e.g., `f: A \to B`)
+
 - **Simplification Rules**: Added and fixed several simplification rules:
   - `x + x` now correctly simplifies to `2x` (term combination)
   - `e^x * e^{-x}` now correctly simplifies to `1` (exponential inverse)

src/compute-engine/latex-syntax/dictionary/definitions-algebra.ts

@@ -7,10 +7,4 @@ export const DEFINITIONS_ALGEBRA: LatexDictionary = [
     kind: 'infix',
     precedence: 270, // MathML rightwards arrow
   },
-  {
-    latexTrigger: ['\\rightarrow'],
-    kind: 'infix',
-    precedence: 270, // MathML rightwards arrow
-    parse: 'To',
-  },
 ];

src/compute-engine/latex-syntax/dictionary/definitions-logic.ts

@@ -159,6 +159,13 @@ export const DEFINITIONS_LOGIC: LatexDictionary = [
     associativity: 'right',
     parse: 'Implies',
   },
+  {
+    latexTrigger: ['\\rightarrow'],
+    kind: 'infix',
+    precedence: 220,
+    associativity: 'right',
+    parse: 'Implies',
+  },
 
   {
     name: 'Equivalent', // MathML: identical to, Mathematica: Congruent
@@ -174,6 +181,13 @@ export const DEFINITIONS_LOGIC: LatexDictionary = [
     precedence: 219,
     parse: 'Equivalent',
   },
+  {
+    latexTrigger: ['\\leftrightarrow'],
+    kind: 'infix',
+    associativity: 'right',
+    precedence: 219,
+    parse: 'Equivalent',
+  },
   {
     latexTrigger: ['\\equiv'],
     kind: 'infix',