lambda

Lambda is a lambda calculus interpreter. It also will convert lambda expression
into the combinators S, K, and I.

Current features:
* Load predefined lambda expression
* Many definitions provided: numbers Y fact map iszero list 1st 2nd 3rd
ADD MUL EXP list suc pred . . .
* Automatic number definitions.
* Interpret lambda expressions.
* Single step interpretation.
* Normal or application order reductions.
* Variable extraction (Conversion to S K I)
* List definitions.
* Some lambda calculus theory.