unknown Initial ITS Start location: [1] Program variables: x y 0: [1] -> [2] : x'=nondet, T, cost: 1 1: [2] -> [3] : x > 0, cost: 1 9: [2] -> [9] : x <= 0, cost: 1 2: [3] -> [4] : y'=0, T, cost: 1 3: [4] -> [5] : y-x < 0, cost: 1 6: [4] -> [7] : y-x >= 0, cost: 1 4: [5] -> [6] : y'=1+y, T, cost: 1 5: [6] -> [4] : T, cost: 1 7: [7] -> [8] : x'=-1+x, T, cost: 1 8: [8] -> [2] : T, cost: 1 Chained Linear Paths Start location: [1] Program variables: x y 0: [1] -> [2] : x'=nondet, T, cost: 1 9: [2] -> [9] : x <= 0, cost: 1 10: [2] -> [4] : y'=0, x > 0, cost: 1 13: [4] -> [4] : y'=1+y, y-x < 0, cost: 1 14: [4] -> [2] : x'=-1+x, y-x >= 0, cost: 1 Eliminating location [3] by chaining: Applied chaining First rule: [2] -> [3] : x > 0, cost: 1 Second rule: [3] -> [4] : y'=0, T, cost: 1 New rule: [2] -> [4] : y'=0, x > 0, cost: 1 Applied deletion Removed the following rules: 1 2 Eliminating location [5] by chaining: Applied chaining First rule: [4] -> [5] : y-x < 0, cost: 1 Second rule: [5] -> [6] : y'=1+y, T, cost: 1 New rule: [4] -> [6] : y'=1+y, y-x < 0, cost: 1 Applied deletion Removed the following rules: 3 4 Eliminating location [7] by chaining: Applied chaining First rule: [4] -> [7] : y-x >= 0, cost: 1 Second rule: [7] -> [8] : x'=-1+x, T, cost: 1 New rule: [4] -> [8] : x'=-1+x, y-x >= 0, cost: 1 Applied deletion Removed the following rules: 6 7 Eliminating location [6] by chaining: Applied chaining First rule: [4] -> [6] : y'=1+y, y-x < 0, cost: 1 Second rule: [6] -> [4] : T, cost: 1 New rule: [4] -> [4] : y'=1+y, y-x < 0, cost: 1 Applied deletion Removed the following rules: 5 11 Eliminating location [8] by chaining: Applied chaining First rule: [4] -> [8] : x'=-1+x, y-x >= 0, cost: 1 Second rule: [8] -> [2] : T, cost: 1 New rule: [4] -> [2] : x'=-1+x, y-x >= 0, cost: 1 Applied deletion Removed the following rules: 8 12 Step with 0 Trace 0[T] Blocked [{}, {}] Step with 9 Trace 0[T], 9[(x <= 0)] Blocked [{}, {}, {}] Backtrack Trace 0[T] Blocked [{}, {9[T]}] Step with 10 Trace 0[T], 10[(x > 0)] Blocked [{}, {9[T]}, {}] Step with 13 Trace 0[T], 10[(x > 0)], 13[(y-x < 0)] Blocked [{}, {9[T]}, {}, {}] Accelerate Start location: [1] Program variables: x y 0: [1] -> [2] : x'=nondet, T, cost: 1 9: [2] -> [9] : x <= 0, cost: 1 10: [2] -> [4] : y'=0, x > 0, cost: 1 13: [4] -> [4] : y'=1+y, y-x < 0, cost: 1 14: [4] -> [2] : x'=-1+x, y-x >= 0, cost: 1 15: [4] -> [4] : y'=n+y, (1-n-y+x > 0 /\ -1+n >= 0), cost: 1 Loop Acceleration Original rule: [4] -> [4] : y'=1+y, (y-x < 0), cost: 1 New rule: [4] -> [4] : y'=n+y, (1-n-y+x > 0 /\ -1+n >= 0), cost: 1 -y+x > 0 [0]: montonic decrease yields 1-n-y+x > 0 -y+x > 0 [1]: eventual increase yields (1 <= 0 /\ -y+x > 0) Replacement map: {-y+x > 0 -> 1-n-y+x > 0} Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}] Step with 14 Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)], 14[(y-x >= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {}] Accelerate Start location: [1] Program variables: x y 0: [1] -> [2] : x'=nondet, T, cost: 1 9: [2] -> [9] : x <= 0, cost: 1 10: [2] -> [4] : y'=0, x > 0, cost: 1 16: [2] -> [2] : x'=-n2+x, y'=1-n2+x, (-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0), cost: 1 13: [4] -> [4] : y'=1+y, y-x < 0, cost: 1 14: [4] -> [2] : x'=-1+x, y-x >= 0, cost: 1 15: [4] -> [4] : y'=n+y, (1-n-y+x > 0 /\ -1+n >= 0), cost: 1 Loop Acceleration Original rule: [2] -> [2] : x'=-1+x, y'=x, (-1+x >= 0 /\ x > 0), cost: 1 New rule: [2] -> [2] : x'=-n2+x, y'=1-n2+x, (-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0), cost: 1 -1+x >= 0 [0]: montonic decrease yields -n2+x >= 0 -1+x >= 0 [1]: eventual increase yields (1 <= 0 /\ -1+x >= 0) x > 0 [0]: montonic decrease yields 1-n2+x > 0 x > 0 [1]: eventual increase yields (1 <= 0 /\ x > 0) Replacement map: {-1+x >= 0 -> -n2+x >= 0, x > 0 -> 1-n2+x > 0} Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)] Blocked [{}, {9[T]}, {16[T]}] Step with 9 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 9[(x <= 0)] Blocked [{}, {9[T]}, {16[T]}, {}] Backtrack Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}] Step with 10 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {}] Step with 15 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T]}, {15[T]}] Step with 13 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)], 13[(y-x < 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T]}, {15[T]}, {}] Covered Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T]}, {13[T], 15[T]}] Step with 14 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)], 14[(y-x >= 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T]}, {13[T], 15[T]}, {}] Covered Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T]}, {13[T], 14[T], 15[T]}] Backtrack Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T], 15[T]}] Step with 13 Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)], 13[(y-x < 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {14[T], 15[T]}, {}] Covered Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)], 10[(x > 0)] Blocked [{}, {9[T]}, {9[T], 16[T]}, {13[T], 14[T], 15[T]}] Backtrack Trace 0[T], 16[(-1+n2 >= 0 /\ 1-n2+x > 0 /\ -n2+x >= 0)] Blocked [{}, {9[T]}, {9[T], 10[T], 16[T]}] Backtrack Trace 0[T] Blocked [{}, {9[T], 16[T]}] Step with 10 Trace 0[T], 10[(x > 0)] Blocked [{}, {9[T], 16[T]}, {}] Step with 13 Trace 0[T], 10[(x > 0)], 13[(y-x < 0)] Blocked [{}, {9[T], 16[T]}, {}, {}] Covered Trace 0[T], 10[(x > 0)] Blocked [{}, {9[T], 16[T]}, {13[T]}] Step with 15 Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T]}, {15[T]}] Step with 13 Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)], 13[(y-x < 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T]}, {15[T]}, {}] Covered Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T]}, {13[T], 15[T]}] Step with 14 Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)], 14[(y-x >= 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T]}, {13[T], 15[T]}, {}] Covered Trace 0[T], 10[(x > 0)], 15[(1-n-y+x > 0 /\ -1+n >= 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T]}, {13[T], 14[T], 15[T]}] Backtrack Trace 0[T], 10[(x > 0)] Blocked [{}, {9[T], 16[T]}, {13[T], 14[T], 15[T]}] Backtrack Trace 0[T] Blocked [{}, {9[T], 10[T], 16[T]}] Backtrack Trace Blocked [{0[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b