ocas-rewrite 0.13.1

Pattern matching and rewriting for oCAS.

This crate builds on [ocas_atom::Atom] and provides:

• A [Pattern] type with wildcards of three levels.
• A [match_pattern] engine that binds wildcards to sub-expressions.
• A [transform] function for bottom-up tree rewriting.
• A [Rule] abstraction and a simplify() entry point.