A witness is a value that witnesses some sort of constraint on some list of type variables. This library provides support for simple witnesses, that constrain a type variable to a single type, and equality witnesses, that constrain two type variables to be the same type. The library also provides classes for representatives, which are values that represent types.
A continuation-based, backtracking, logic programming monad. An adaptation of the two-continuation implementation found in the paper Backtracking, Interleaving, and Terminating Monad Transformers available here: http://okmij.org/ Control.Monad.Logic.Class