; @author Jonas Schöpf
; Ctrl example from examples/student/fib06.ctrs
(format LCTRS :smtlib 2.6)

(theory Ints)

(sort Unit)

(fun v (-> Int Int Int Int Int Unit))
(fun return (-> Int Unit))
(fun u (-> Int Int Int Int Int Unit))
(fun fastfib (-> Int Unit))

(rule (v n i fb p q) (return fb) :guard (not (<= i n)))
(rule (v n i fb p q) (v n (+ i 1) (+ p q) (+ p q) p) :guard (<= i n))
(rule (u n i fb p q) (v n 2 fb p q) :guard (and (not (< n 1)) (not (= n 1))) :var ((n Int)))
(rule (u n i fb p q) (return 1) :guard (and (not (< n 1)) (= n 1)) :var ((n Int)))
(rule (u n i fb p q) (return 0) :guard (< n 1))
(rule (fastfib n) (u n rnd1 rnd2 1 0))