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] : x > 0, cost: 1 9: [3] -> [9] : x <= 0, cost: 1 3: [4] -> [5] : y > 0, cost: 1 6: [4] -> [7] : y <= 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] -> [3] : T, cost: 1 Chained Linear Paths Start location: [1] Program variables: x y 10: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 2: [3] -> [4] : x > 0, cost: 1 9: [3] -> [9] : x <= 0, cost: 1 13: [4] -> [4] : y'=-1+y, y > 0, cost: 1 14: [4] -> [3] : x'=-1+x, 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 [5] by chaining: Applied chaining First rule: [4] -> [5] : y > 0, cost: 1 Second rule: [5] -> [6] : y'=-1+y, T, cost: 1 New rule: [4] -> [6] : y'=-1+y, y > 0, cost: 1 Applied deletion Removed the following rules: 3 4 Eliminating location [7] by chaining: Applied chaining First rule: [4] -> [7] : y <= 0, cost: 1 Second rule: [7] -> [8] : x'=-1+x, T, cost: 1 New rule: [4] -> [8] : x'=-1+x, y <= 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 > 0, cost: 1 Second rule: [6] -> [4] : T, cost: 1 New rule: [4] -> [4] : y'=-1+y, y > 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 <= 0, cost: 1 Second rule: [8] -> [3] : T, cost: 1 New rule: [4] -> [3] : x'=-1+x, y <= 0, cost: 1 Applied deletion Removed the following rules: 8 12 Step with 10 Trace 10[T] Blocked [{}, {}] Step with 9 Trace 10[T], 9[(x <= 0)] Blocked [{}, {}, {}] Backtrack Trace 10[T] Blocked [{}, {9[T]}] Step with 2 Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T]}, {}] Step with 13 Trace 10[T], 2[(x > 0)], 13[(y > 0)] Blocked [{}, {9[T]}, {}, {}] Accelerate Start location: [1] Program variables: x y 10: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 2: [3] -> [4] : x > 0, cost: 1 9: [3] -> [9] : x <= 0, cost: 1 13: [4] -> [4] : y'=-1+y, y > 0, cost: 1 14: [4] -> [3] : x'=-1+x, y <= 0, cost: 1 15: [4] -> [4] : y'=-n+y, (-1+n >= 0 /\ 1-n+y > 0), cost: 1 Loop Acceleration Original rule: [4] -> [4] : y'=-1+y, (y > 0), cost: 1 New rule: [4] -> [4] : y'=-n+y, (-1+n >= 0 /\ 1-n+y > 0), cost: 1 y > 0 [0]: montonic decrease yields 1-n+y > 0 y > 0 [1]: eventual increase yields (1 <= 0 /\ y > 0) Replacement map: {y > 0 -> 1-n+y > 0} Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {}] Acceleration Failed marked recursive suffix as redundant Step with 2 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {}, {}] Accelerate Start location: [1] Program variables: x y 10: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 2: [3] -> [4] : x > 0, cost: 1 9: [3] -> [9] : x <= 0, cost: 1 13: [4] -> [4] : y'=-1+y, y > 0, cost: 1 14: [4] -> [3] : x'=-1+x, y <= 0, cost: 1 15: [4] -> [4] : y'=-n+y, (-1+n >= 0 /\ 1-n+y > 0), cost: 1 16: [4] -> [4] : x'=-n2+x, (-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0), cost: 1 Loop Acceleration Original rule: [4] -> [4] : x'=-1+x, (y <= 0 /\ -1+x > 0), cost: 1 New rule: [4] -> [4] : x'=-n2+x, (-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0), cost: 1 -y >= 0 [0]: monotonic increase yields -y >= 0 -1+x > 0 [0]: montonic decrease yields -n2+x > 0 -1+x > 0 [1]: eventual increase yields (1 <= 0 /\ -1+x > 0) Replacement map: {-y >= 0 -> -y >= 0, -1+x > 0 -> -n2+x > 0} Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {16[T]}] Acceleration Failed marked recursive suffix as redundant Step with 14 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 16[T]}, {}] Acceleration Failed marked recursive suffix as redundant Step with 2 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 16[T]}, {}, {}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 16[T]}, {2[T]}] Step with 9 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)], 9[(x <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 16[T]}, {2[T]}, {}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 16[T]}, {2[T], 9[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T]}, {13[T], 14[T], 16[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}, {}] Step with 9 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 9[(x <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}, {}, {}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}, {9[T]}] Step with 2 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}, {9[T]}, {}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {}, {13[T], 15[T], 16[T]}, {2[T], 9[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T]}, {}, {13[T], 14[T], 15[T], 16[T]}] Backtrack Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T]}, {15[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {15[T]}, {}] Accelerate Start location: [1] Program variables: x y 10: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 2: [3] -> [4] : x > 0, cost: 1 9: [3] -> [9] : x <= 0, cost: 1 17: [3] -> [3] : x'=-n3+x, (-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0), cost: 1 13: [4] -> [4] : y'=-1+y, y > 0, cost: 1 14: [4] -> [3] : x'=-1+x, y <= 0, cost: 1 15: [4] -> [4] : y'=-n+y, (-1+n >= 0 /\ 1-n+y > 0), cost: 1 16: [4] -> [4] : x'=-n2+x, (-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0), cost: 1 Loop Acceleration Original rule: [3] -> [3] : x'=-1+x, (y <= 0 /\ x > 0), cost: 1 New rule: [3] -> [3] : x'=-n3+x, (-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0), cost: 1 -y >= 0 [0]: monotonic increase yields -y >= 0 x > 0 [0]: montonic decrease yields 1-n3+x > 0 x > 0 [1]: eventual increase yields (1 <= 0 /\ x > 0) Replacement map: {-y >= 0 -> -y >= 0, x > 0 -> 1-n3+x > 0} Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)] Blocked [{}, {9[T]}, {17[T]}] Step with 9 Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 9[(x <= 0)] Blocked [{}, {9[T]}, {17[T]}, {}] Backtrack Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}] Step with 2 Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {}] Step with 14 Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {}, {}] Covered Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {14[T]}] Step with 16 Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {14[T], 15[T]}, {16[T]}] Step with 14 Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {14[T], 15[T]}, {13[T], 16[T]}, {}] Covered Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {14[T], 15[T]}, {13[T], 14[T], 16[T]}] Backtrack Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)], 2[(x > 0)] Blocked [{}, {9[T]}, {9[T], 17[T]}, {14[T], 15[T], 16[T]}] Backtrack Trace 10[T], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)] Blocked [{}, {9[T]}, {2[T], 9[T], 17[T]}] Backtrack Trace 10[T] Blocked [{}, {9[T], 17[T]}] Step with 2 Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {}] Step with 14 Trace 10[T], 2[(x > 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {}, {}] Covered Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}] Step with 15 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}] Step with 16 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {16[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {}] Step with 2 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {}, {}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {2[T]}] Step with 17 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {2[T]}, {17[T]}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {2[T], 17[T]}] Step with 9 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)], 9[(x <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {2[T], 17[T]}, {}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 16[T]}, {2[T], 9[T], 17[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T]}, {13[T], 14[T], 16[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {}] Step with 9 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 9[(x <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {}, {}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {9[T]}] Step with 2 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {9[T]}, {}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {2[T], 9[T]}] Step with 17 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)], 17[(-1+n3 >= 0 /\ -y >= 0 /\ 1-n3+x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {2[T], 9[T]}, {17[T]}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {15[T], 16[T]}, {2[T], 9[T], 17[T]}] Backtrack Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {14[T], 15[T], 16[T]}] Step with 13 Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)], 13[(y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {14[T], 15[T], 16[T]}, {}] Covered Trace 10[T], 2[(x > 0)], 15[(-1+n >= 0 /\ 1-n+y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T]}, {13[T], 14[T], 15[T], 16[T]}] Backtrack Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {14[T], 15[T]}] Step with 13 Trace 10[T], 2[(x > 0)], 13[(y > 0)] Blocked [{}, {9[T], 17[T]}, {14[T], 15[T]}, {}] Covered Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {13[T], 14[T], 15[T]}] Step with 16 Trace 10[T], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T], 17[T]}, {13[T], 14[T], 15[T]}, {16[T]}] Step with 14 Trace 10[T], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)], 14[(y <= 0)] Blocked [{}, {9[T], 17[T]}, {13[T], 14[T], 15[T]}, {13[T], 16[T]}, {}] Covered Trace 10[T], 2[(x > 0)], 16[(-n2+x > 0 /\ -y >= 0 /\ -1+n2 >= 0)] Blocked [{}, {9[T], 17[T]}, {13[T], 14[T], 15[T]}, {13[T], 14[T], 16[T]}] Backtrack Trace 10[T], 2[(x > 0)] Blocked [{}, {9[T], 17[T]}, {13[T], 14[T], 15[T], 16[T]}] Backtrack Trace 10[T] Blocked [{}, {2[T], 9[T], 17[T]}] Backtrack Trace Blocked [{10[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b