You might be thinking of Total Functional Programming [0] "a programming paradigm that restricts the range of programs to those that are provably terminating."

You might be thinking of Total Functional Programming [0] "a programming paradigm that restricts the range of programs to those that are provably terminating." [0] https://en.wikipedia.org/wiki/Total_functional_programming https://en.wikipedia.org/wiki/Total_functional_programming