This module is an extension to the Math::Symbolic module. A basic 
familiarity with that module is required.

The Math::Symbolic::Custom::Pattern module implements pattern matching 
routines on Math::Symbolic trees. The patterns itself are constructed from 
Math::Symbolic trees with just a few variables which have a special 
meaning.

The module provides two interfaces. You can use the new() and match() 
methods this class provides, or you can use the to_pattern() and 
is_of_form() methods on any Math::Symbolic tree. (Exported by the 
Math::Symbolic::Custom::Pattern::Export module. Refer to that module for 
details on is_of_form().)

WWW: http://search.cpan.org/dist/Math-Symbolic-Custom-Pattern