Convergence of recursive functions on computers
A theorem is presented which has applications in the numerical computation of fixed points of recursive functions. If a sequence of functions {fn } is convergent on a metric space I ⊆ ℝ, then it is possible to observe this behaviour on the set 𝔻 ⊂ ℚ of all numbers represented in a computer. However, as 𝔻 is not complete, the representation of fn on 𝔻 is subject to an error. Then fn and fm are considered equal when its differences computed on 𝔻 are equal or lower than the sum of error of each fn and fm . An example is given to illustrate the use of the theorem.