cond
(cond (case1 do-when-case1) (case2 do-when-case2) ... (t do-when-none-meet)) (defun fib (n) (cond ((= n 0) 0) ((= n 1) 1) (t (+ (fib (- n 1)) (fib (- n 2)))))) (fib 10) ; => 55