Editing Lambda calculus (section)

== Variations and extensions ==
These extensions are in the [[lambda cube]]:
* [[Typed lambda calculus]] – Lambda calculus with typed variables (and functions)
* [[System F]] – A typed lambda calculus with type-variables
* [[Calculus of constructions]] – A typed lambda calculus with types as first-class values

These [[formal system]]s are extensions of lambda calculus that are not in the lambda cube:
* [[Binary lambda calculus]] – A version of lambda calculus with binary [[input/output]] (I/O), a binary encoding of terms, and a designated universal machine.
* [[Lambda-mu calculus]] – An extension of the lambda calculus for treating [[classical logic]]

These formal systems are variations of lambda calculus:
* [[Kappa calculus]] – A first-order analogue of lambda calculus

These formal systems are related to lambda calculus:
* [[Combinatory logic]] – A notation for mathematical logic without variables
* [[SKI combinator calculus]] – A computational system based on the '''[[#S|S]]''', '''[[#K|K]]''' and '''[[#I|I]]''' combinators, equivalent to lambda calculus, but reducible without variable substitutions