in mathematical logic and computer science, lambda calculus, also λ-calculus, is a formal system (a system that can be used to figure out different logical theories and ideas). it was made to explore different ways of creating and using mathematical functions, and it lays out rules for doing this. it is also a tool for exploring recursion, and it has been used to explain what a computable function is. it was made by alonzo church and stephen cole kleene in the 1930s. in 1936, church used lambda calculus to show that there is no solution to the entscheidungsproblem.