MAYBE Initial complexity problem: 1: T: (Comp: ?, Cost: 1) f0(Ar_0, Ar_1) -> Com_1(f1(3000, Ar_1)) (Comp: ?, Cost: 1) f1(Ar_0, Ar_1) -> Com_1(f1(Ar_0, Ar_1 + 1000)) [ Ar_1 + 889 >= 0 /\ 3999 >= Ar_0 ] (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(f0(Ar_0, Ar_1)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Repeatedly propagating knowledge in problem 1 produces the following problem: 2: T: (Comp: 1, Cost: 1) f0(Ar_0, Ar_1) -> Com_1(f1(3000, Ar_1)) (Comp: ?, Cost: 1) f1(Ar_0, Ar_1) -> Com_1(f1(Ar_0, Ar_1 + 1000)) [ Ar_1 + 889 >= 0 /\ 3999 >= Ar_0 ] (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(f0(Ar_0, Ar_1)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Applied AI with 'oct' on problem 2 to obtain the following invariants: For symbol f1: -X_1 + 3000 >= 0 /\ X_1 - 3000 >= 0 This yielded the following problem: 3: T: (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(f0(Ar_0, Ar_1)) [ 0 <= 0 ] (Comp: ?, Cost: 1) f1(Ar_0, Ar_1) -> Com_1(f1(Ar_0, Ar_1 + 1000)) [ -Ar_0 + 3000 >= 0 /\ Ar_0 - 3000 >= 0 /\ Ar_1 + 889 >= 0 /\ 3999 >= Ar_0 ] (Comp: 1, Cost: 1) f0(Ar_0, Ar_1) -> Com_1(f1(3000, Ar_1)) start location: koat_start leaf cost: 0 Complexity upper bound ? Time: 0.721 sec (SMT: 0.692 sec)