MAYBE Initial complexity problem: 1: T: (Comp: ?, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0 - 1, Ar_1, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: ?, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1 + Ar_2, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: ?, Cost: 1) start(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(start(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Repeatedly propagating knowledge in problem 1 produces the following problem: 2: T: (Comp: ?, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0 - 1, Ar_1, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: ?, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1 + Ar_2, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: 1, Cost: 1) start(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(start(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 A polynomial rank function with Pol(eval) = V_1 + 1 Pol(start) = V_1 + 1 Pol(koat_start) = V_1 + 1 orients all transitions weakly and the transition eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0 - 1, Ar_1, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] strictly and produces the following problem: 3: T: (Comp: Ar_0 + 1, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0 - 1, Ar_1, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: ?, Cost: 1) eval(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1 + Ar_2, Ar_2 - 1)) [ Ar_0 >= 0 /\ Ar_1^3 >= Ar_2 ] (Comp: 1, Cost: 1) start(Ar_0, Ar_1, Ar_2) -> Com_1(eval(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(start(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Complexity upper bound ? Time: 0.945 sec (SMT: 0.908 sec)