unknown Initial ITS Start location: [1] Program variables: x y 0: [1] -> [2] : x'=nondet, T, cost: 1 1: [2] -> [3] : y'=nondet1, T, cost: 1 2: [3] -> [4] : (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 6: [3] -> [7] : (-2+y > 0 \/ -y+x <= 0 \/ -1+y < 0), cost: 1 3: [4] -> [5] : x'=-y+x, T, cost: 1 4: [5] -> [6] : y'=nondet2, T, cost: 1 5: [6] -> [3] : T, cost: 1 Chained Linear Paths Start location: [1] Program variables: x y 7: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 6: [3] -> [7] : (-2+y > 0 \/ -y+x <= 0 \/ -1+y < 0), cost: 1 10: [3] -> [3] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Eliminating location [2] by chaining: Applied chaining First rule: [1] -> [2] : x'=nondet, T, cost: 1 Second rule: [2] -> [3] : y'=nondet1, T, cost: 1 New rule: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 Applied deletion Removed the following rules: 0 1 Eliminating location [4] by chaining: Applied chaining First rule: [3] -> [4] : (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Second rule: [4] -> [5] : x'=-y+x, T, cost: 1 New rule: [3] -> [5] : x'=-y+x, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Applied deletion Removed the following rules: 2 3 Eliminating location [5] by chaining: Applied chaining First rule: [3] -> [5] : x'=-y+x, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Second rule: [5] -> [6] : y'=nondet2, T, cost: 1 New rule: [3] -> [6] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Applied deletion Removed the following rules: 4 8 Eliminating location [6] by chaining: Applied chaining First rule: [3] -> [6] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Second rule: [6] -> [3] : T, cost: 1 New rule: [3] -> [3] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 Applied deletion Removed the following rules: 5 9 Step with 7 Trace 7[T] Blocked [{}, {}] Step with 6 Trace 7[T], 6[(-y+x <= 0)] Blocked [{}, {}, {}] Backtrack Trace 7[T] Blocked [{}, {6[-y+x <= 0]}] Step with 6 Trace 7[T], 6[(-1+y < 0)] Blocked [{}, {6[-y+x <= 0]}, {}] Backtrack Trace 7[T] Blocked [{}, {6[(-y+x <= 0 /\ -1+y < 0)]}] Step with 6 Trace 7[T], 6[(-2+y > 0)] Blocked [{}, {6[(-y+x <= 0 /\ -1+y < 0)]}, {}] Backtrack Trace 7[T] Blocked [{}, {6[(-2+y > 0 /\ -y+x <= 0 /\ -1+y < 0)]}] Step with 10 Trace 7[T], 10[(-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0)] Blocked [{}, {6[T]}, {}] Accelerate Start location: [1] Program variables: x y 7: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 6: [3] -> [7] : (-2+y > 0 \/ -y+x <= 0 \/ -1+y < 0), cost: 1 10: [3] -> [3] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 11: [3] -> [3] : x'=-nondet2*n+x, y'=nondet2, (2-nondet2 >= 0 /\ -1+nondet2 >= 0 /\ -y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0 /\ 2-y >= 0 /\ -1+y >= 0 /\ -1+n >= 0), cost: 1 Loop Acceleration Original rule: [3] -> [3] : x'=-y+x, y'=nondet2, (-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0), cost: 1 New rule: [3] -> [3] : x'=-nondet2*n+x, y'=nondet2, (2-nondet2 >= 0 /\ -1+nondet2 >= 0 /\ -y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0 /\ 2-y >= 0 /\ -1+y >= 0 /\ -1+n >= 0), cost: 1 -y+x > 0 [0]: eventual decrease yields (-y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0) -y+x > 0 [1]: eventual increase yields (nondet2 <= 0 /\ -y+x > 0) 2-y >= 0 [0]: eventual decrease yields (2-nondet2 >= 0 /\ 2-y >= 0) 2-y >= 0 [1]: eventual increase yields (nondet2-y <= 0 /\ 2-y >= 0) -1+y >= 0 [0]: eventual decrease yields (-1+nondet2 >= 0 /\ -1+y >= 0) -1+y >= 0 [1]: eventual increase yields (-nondet2+y <= 0 /\ -1+y >= 0) Replacement map: {-y+x > 0 -> (-y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0), 2-y >= 0 -> (2-nondet2 >= 0 /\ 2-y >= 0), -1+y >= 0 -> (-1+nondet2 >= 0 /\ -1+y >= 0)} Trace 7[T], 11[(2-nondet2 >= 0 /\ -1+nondet2 >= 0 /\ -y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0 /\ 2-y >= 0 /\ -1+y >= 0 /\ -1+n >= 0)] Blocked [{}, {6[T]}, {10[T], 11[T]}] Step with 6 Trace 7[T], 11[(2-nondet2 >= 0 /\ -1+nondet2 >= 0 /\ -y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0 /\ 2-y >= 0 /\ -1+y >= 0 /\ -1+n >= 0)], 6[(-y+x <= 0)] Blocked [{}, {6[T]}, {10[T], 11[T]}, {}] Backtrack Trace 7[T], 11[(2-nondet2 >= 0 /\ -1+nondet2 >= 0 /\ -y+x > 0 /\ -nondet2-nondet2*(-1+n)+x > 0 /\ 2-y >= 0 /\ -1+y >= 0 /\ -1+n >= 0)] Blocked [{}, {6[T]}, {6[-y+x <= 0], 10[T], 11[T]}] Backtrack Trace 7[T] Blocked [{}, {6[T], 11[T]}] Step with 10 Trace 7[T], 10[(-2+y <= 0 /\ -y+x > 0 /\ -1+y >= 0)] Blocked [{}, {6[T], 11[T]}, {}] Covered Trace 7[T] Blocked [{}, {6[T], 10[T], 11[T]}] Backtrack Trace Blocked [{7[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b