(calc.info)Rewrite Rules

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12.11 Rewrite Rules
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The `a r' (`calc-rewrite') [`rewrite'] command makes substitutions in a
formula according to a specified pattern or patterns known as "rewrite
rules".  Whereas `a b' (`calc-substitute') matches literally, so that
substituting `sin(x)' with `cos(x)' matches only the `sin' function
applied to the variable `x', rewrite rules match general kinds of
formulas; rewriting using the rule `sin(x) := cos(x)' matches `sin' of
any argument and replaces it with `cos' of that same argument.  The
only significance of the name `x' is that the same name is used on both
sides of the rule.

   Rewrite rules rearrange formulas already in Calc's memory.  Note:
Syntax Tables, to read about "syntax rules", which are similar to
algebraic rewrite rules but operate when new algebraic entries are
being parsed, converting strings of characters into Calc formulas.

Entering Rewrite Rules

Basic Rewrite Rules

Conditional Rewrite Rules

Algebraic Properties of Rewrite Rules

Other Features of Rewrite Rules

Composing Patterns in Rewrite Rules

Nested Formulas with Rewrite Rules

Multi-Phase Rewrite Rules

Selections with Rewrite Rules

Matching Commands

Automatic Rewrites

Debugging Rewrites

Examples of Rewrite Rules