WORST_CASE(?, O(n^1)) Initial complexity problem: 1: T: (Comp: ?, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ] (Comp: ?, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ] (Comp: ?, Cost: 1) start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(start(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: ?, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ] (Comp: ?, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ] (Comp: 1, Cost: 1) start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 A polynomial rank function with Pol(sumto) = 1 Pol(end) = 0 Pol(start) = 1 Pol(koat_start) = 1 orients all transitions weakly and the transition sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ] strictly and produces the following problem: 3: T: (Comp: 1, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ] (Comp: ?, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ] (Comp: 1, Cost: 1) start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 A polynomial rank function with Pol(sumto) = -V_1 + V_2 + 1 Pol(end) = -V_1 + V_2 + 1 Pol(start) = -V_1 + V_2 + 1 Pol(koat_start) = -V_1 + V_2 + 1 orients all transitions weakly and the transition sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ] strictly and produces the following problem: 4: T: (Comp: 1, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ] (Comp: Ar_0 + Ar_1 + 1, Cost: 1) sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ] (Comp: 1, Cost: 1) start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1)) (Comp: 1, Cost: 0) koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ] start location: koat_start leaf cost: 0 Complexity upper bound Ar_0 + Ar_1 + 3 Time: 0.262 sec (SMT: 0.251 sec)