For 10 points, name this type of function that calls upon previous values of itself.
Type 0 languages have the property of being enumerated in this fashion. Higher order functions such as fold-right and map operate in this fashion. The fixed-point Y combinator can be used to define these functions in the lambda calculus. A common optimization to reduce the amount of space on a stack is to make a tail call on this type of process. An example of a function of this type that possesses a closed form is the Fibonacci sequence. Like induction, this type of function begins by defining a base case. For 10 points, name this type of function that calls upon previous values of itself.
Type 0 languages have the property of being enumerated in this fashion.
recursive [accept word forms such as recursion]