Rho calculus
Encyclopedia
The rho-calculus is a formalism intended to combine the higher-order facilities of lambda calculus
with the pattern matching of term rewriting.
Lambda calculus
In mathematical logic and computer science, lambda calculus, also written as λ-calculus, is a formal system for function definition, function application and recursion. The portion of lambda calculus relevant to computation is now called the untyped lambda calculus...
with the pattern matching of term rewriting.