MAYBE Initial complexity problem: 1: T: (Comp: ?, Cost: 1) eval_ex3_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_0(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_0(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_1(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_1(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_2(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_2(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_3(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_3(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_4(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_4(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_2, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2)) [ 0 < Ar_0 /\ Ar_0 < 255 ] (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ 0 >= Ar_0 ] (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 255 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 < 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 > 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_1 = 0 ] (Comp: ?, Cost: 1) eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_stop(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_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: 1, Cost: 1) eval_ex3_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_0(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_0(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_1(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_1(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_2(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_2(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_3(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_3(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_4(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_4(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_2, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2)) [ 0 < Ar_0 /\ Ar_0 < 255 ] (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ 0 >= Ar_0 ] (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 255 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 < 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 > 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_1 = 0 ] (Comp: ?, Cost: 1) eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_stop(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_start(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 A polynomial rank function with Pol(eval_ex3_start) = 2 Pol(eval_ex3_bb0_in) = 2 Pol(eval_ex3_0) = 2 Pol(eval_ex3_1) = 2 Pol(eval_ex3_2) = 2 Pol(eval_ex3_3) = 2 Pol(eval_ex3_4) = 2 Pol(eval_ex3_bb1_in) = 2 Pol(eval_ex3_bb2_in) = 2 Pol(eval_ex3_bb3_in) = 1 Pol(eval_ex3_stop) = 0 Pol(koat_start) = 2 orients all transitions weakly and the transitions eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_stop(Ar_0, Ar_1, Ar_2)) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 255 ] eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ 0 >= Ar_0 ] strictly and produces the following problem: 3: T: (Comp: 1, Cost: 1) eval_ex3_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_0(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_0(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_1(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_1(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_2(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_2(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_3(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_3(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_4(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_4(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_2, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2)) [ 0 < Ar_0 /\ Ar_0 < 255 ] (Comp: 2, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ 0 >= Ar_0 ] (Comp: 2, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 255 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 < 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ Ar_1 > 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 - 1, Ar_1, Ar_2)) [ Ar_1 = 0 ] (Comp: 2, Cost: 1) eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_stop(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_start(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 eval_ex3_bb2_in: -X_1 + 254 >= 0 /\ X_1 - 1 >= 0 This yielded the following problem: 4: T: (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_start(Ar_0, Ar_1, Ar_2)) [ 0 <= 0 ] (Comp: 2, Cost: 1) eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_stop(Ar_0, Ar_1, Ar_2)) (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 - 1, Ar_1, Ar_2)) [ -Ar_0 + 254 >= 0 /\ Ar_0 - 1 >= 0 /\ Ar_1 = 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ -Ar_0 + 254 >= 0 /\ Ar_0 - 1 >= 0 /\ Ar_1 > 0 ] (Comp: ?, Cost: 1) eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_0 + 1, Ar_1, Ar_2)) [ -Ar_0 + 254 >= 0 /\ Ar_0 - 1 >= 0 /\ Ar_1 < 0 ] (Comp: 2, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ Ar_0 >= 255 ] (Comp: 2, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb3_in(Ar_0, Ar_1, Ar_2)) [ 0 >= Ar_0 ] (Comp: ?, Cost: 1) eval_ex3_bb1_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb2_in(Ar_0, Ar_1, Ar_2)) [ 0 < Ar_0 /\ Ar_0 < 255 ] (Comp: 1, Cost: 1) eval_ex3_4(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb1_in(Ar_2, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_3(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_4(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_2(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_3(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_1(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_2(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_0(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_1(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_0(Ar_0, Ar_1, Ar_2)) (Comp: 1, Cost: 1) eval_ex3_start(Ar_0, Ar_1, Ar_2) -> Com_1(eval_ex3_bb0_in(Ar_0, Ar_1, Ar_2)) start location: koat_start leaf cost: 0 Complexity upper bound ? Time: 3.042 sec (SMT: 2.963 sec)