Math::Symbolic::Custom::Transformation is an extension to the Math::Symbolic module. You're assumed to be remotely familiar with that module throughout the documentation. This package implements transformations of Math::Symbolic trees using Math::Symbolic trees. I'll try to explain what this means in the following paragraphs. Until now, in order to be able to inspect a Math::Symbolic tree, one had to use the low-level Math::Symbolic interface like comparing the top node's term type with a constant (such as T_OPERATOR) and then its operator type with more constants. This has changed with the release of Math::Symbolic::Custom::Pattern. To modify the tree, you had to use equally low-level or even encapsulation-breaking methods. This is meant to be changed by this distribution. WWW: http://search.cpan.org/dist/Math-Symbolic-Custom-Transformation Author: Steffen Mueller