MAYBE Initial complexity problem: 1: T: (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ 0 >= Ar_1 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_4, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f26(Ar_0, Ar_1, Ar_2) -> Com_1(f27(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) f27(Ar_0, Ar_1, Ar_2) -> Com_1(f27(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) f29(Ar_0, Ar_1, Ar_2) -> Com_1(f32(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_0 >= 3 ] (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0, Fresh_3, Ar_2)) [ 2 >= Ar_0 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_2, Ar_2)) [ 5 >= Ar_0 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ Ar_1 >= 1 ] (Comp: ?, Cost: 1) f0(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Fresh_0, Fresh_1, Fresh_0)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(f0(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Testing for reachability in the complexity graph removes the following transitions from problem 1: f26(Ar_0, Ar_1, Ar_2) -> Com_1(f27(Ar_0, Ar_1, Ar_2)) f27(Ar_0, Ar_1, Ar_2) -> Com_1(f27(Ar_0, Ar_1, Ar_2)) f29(Ar_0, Ar_1, Ar_2) -> Com_1(f32(Ar_0, Ar_1, Ar_2)) We thus obtain the following problem: 2: T: (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0, Fresh_3, Ar_2)) [ 2 >= Ar_0 ] (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_0 >= 3 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_2, Ar_2)) [ 5 >= Ar_0 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_4, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ Ar_1 >= 1 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ 0 >= Ar_1 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f0(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Fresh_0, Fresh_1, Fresh_0)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(f0(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Repeatedly propagating knowledge in problem 2 produces the following problem: 3: T: (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0, Fresh_3, Ar_2)) [ 2 >= Ar_0 ] (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_0 >= 3 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_2, Ar_2)) [ 5 >= Ar_0 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_4, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ Ar_1 >= 1 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ 0 >= Ar_1 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 6 ] (Comp: 1, Cost: 1) f0(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Fresh_0, Fresh_1, Fresh_0)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(f0(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Applied AI with 'oct' on problem 3 to obtain the following invariants: For symbol f20: X_2 - 1 >= 0 /\ -X_1 + X_2 + 4 >= 0 /\ -X_1 + 5 >= 0 This yielded the following problem: 4: T: (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(f0(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] (Comp: 1, Cost: 1) f0(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Fresh_0, Fresh_1, Fresh_0)) (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f14(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ 0 >= Ar_1 ] (Comp: ?, Cost: 1) f11(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0, Ar_1, Ar_2)) [ 5 >= Ar_0 /\ Ar_1 >= 1 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_4, Ar_2)) [ Ar_0 >= 6 ] (Comp: ?, Cost: 1) f14(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0 + 1, Fresh_2, Ar_2)) [ 5 >= Ar_0 ] (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f20(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_1 - 1 >= 0 /\ -Ar_0 + Ar_1 + 4 >= 0 /\ -Ar_0 + 5 >= 0 /\ Ar_0 >= 3 ] (Comp: ?, Cost: 1) f20(Ar_0, Ar_1, Ar_2) -> Com_1(f11(Ar_0, Fresh_3, Ar_2)) [ Ar_1 - 1 >= 0 /\ -Ar_0 + Ar_1 + 4 >= 0 /\ -Ar_0 + 5 >= 0 /\ 2 >= Ar_0 ] start location: koat_start leaf cost: 0 Complexity upper bound ? Time: 2.068 sec (SMT: 2.006 sec)