recursion

In computer science recursion is the act of solving a problem with intermediate results of smaller instances of the same problem. A function used to solve a problem is therefore calling itself within its own definition. This concept is usually supported by most programming languages in addition to the imperative style of programming, which uses control structures such as for and while loops. Some functional programming languages even support recursion as the only method of problem solving. This article is about the definition of recursion in lambda calculus.