lambda calculus
deductive lambda calculus – The consideration of the problems associated with considering lambda calculus as a Deductive system.
domain theory – Study of certain posets giving denotational semantics for lambda calculus
Harrop formula – A kind of constructive logical formula such that proofs are lambda terms
Krivine machine – An abstract machine to interpret call-by-name in lambda calculus
rewriting – Transformation of formulæ in formal systems
SECD machine – A virtual machine designed for the lambda calculus
Unlambda – An esoteric functional programming language based on combinatory logic