The package defines the command \perfectcut#1#2 which displays a bracket <#1||#2>. Its effect is to determine the size of the bracket depending on the number of nested \perfectcut (regardless of the contents). The command is intended for use:

• In proof theory, for term notations of sequent calculus,
• In computer science, for the modeling of abstract machines.

The package also offers a reimplementation of \big, \bigg, etc., into arbitrary-size variants.

The author is Guillaume Munch-Maccagnoni.