unknown Initial ITS Start location: [1] Program variables: c x y 0: [1] -> [2] : x'=nondet, T, cost: 1 1: [2] -> [3] : y'=nondet1, T, cost: 1 2: [3] -> [4] : c'=0, T, cost: 1 3: [4] -> [5] : (y > 0 /\ x > 0), cost: 1 8: [4] -> [9] : (y <= 0 \/ x <= 0), cost: 1 4: [5] -> [6] : x'=-1+x, T, cost: 1 5: [6] -> [7] : y'=-1+y, T, cost: 1 6: [7] -> [8] : c'=1+c, T, cost: 1 7: [8] -> [4] : T, cost: 1 Chained Linear Paths Start location: [1] Program variables: c x y 10: [1] -> [4] : c'=0, x'=nondet, y'=nondet1, T, cost: 1 8: [4] -> [9] : (y <= 0 \/ x <= 0), cost: 1 14: [4] -> [4] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 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 [3] by chaining: Applied chaining First rule: [1] -> [3] : x'=nondet, y'=nondet1, T, cost: 1 Second rule: [3] -> [4] : c'=0, T, cost: 1 New rule: [1] -> [4] : c'=0, x'=nondet, y'=nondet1, T, cost: 1 Applied deletion Removed the following rules: 2 9 Eliminating location [5] by chaining: Applied chaining First rule: [4] -> [5] : (y > 0 /\ x > 0), cost: 1 Second rule: [5] -> [6] : x'=-1+x, T, cost: 1 New rule: [4] -> [6] : x'=-1+x, (y > 0 /\ x > 0), cost: 1 Applied deletion Removed the following rules: 3 4 Eliminating location [6] by chaining: Applied chaining First rule: [4] -> [6] : x'=-1+x, (y > 0 /\ x > 0), cost: 1 Second rule: [6] -> [7] : y'=-1+y, T, cost: 1 New rule: [4] -> [7] : x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 Applied deletion Removed the following rules: 5 11 Eliminating location [7] by chaining: Applied chaining First rule: [4] -> [7] : x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 Second rule: [7] -> [8] : c'=1+c, T, cost: 1 New rule: [4] -> [8] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 Applied deletion Removed the following rules: 6 12 Eliminating location [8] by chaining: Applied chaining First rule: [4] -> [8] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 Second rule: [8] -> [4] : T, cost: 1 New rule: [4] -> [4] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 Applied deletion Removed the following rules: 7 13 Step with 10 Trace 10[T] Blocked [{}, {}] Step with 8 Trace 10[T], 8[(y <= 0)] Blocked [{}, {}, {}] Backtrack Trace 10[T] Blocked [{}, {8[y <= 0]}] Step with 8 Trace 10[T], 8[(x <= 0)] Blocked [{}, {8[y <= 0]}, {}] Backtrack Trace 10[T] Blocked [{}, {8[(y <= 0 /\ x <= 0)]}] Step with 14 Trace 10[T], 14[(y > 0 /\ x > 0)] Blocked [{}, {8[T]}, {}] Accelerate Start location: [1] Program variables: c x y 10: [1] -> [4] : c'=0, x'=nondet, y'=nondet1, T, cost: 1 8: [4] -> [9] : (y <= 0 \/ x <= 0), cost: 1 14: [4] -> [4] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 15: [4] -> [4] : c'=c+n, x'=-n+x, y'=-n+y, (-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0), cost: 1 Loop Acceleration Original rule: [4] -> [4] : c'=1+c, x'=-1+x, y'=-1+y, (y > 0 /\ x > 0), cost: 1 New rule: [4] -> [4] : c'=c+n, x'=-n+x, y'=-n+y, (-1+n >= 0 /\ 1-n+x > 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) x > 0 [0]: montonic decrease yields 1-n+x > 0 x > 0 [1]: eventual increase yields (1 <= 0 /\ x > 0) Replacement map: {y > 0 -> 1-n+y > 0, x > 0 -> 1-n+x > 0} Trace 10[T], 15[(-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0)] Blocked [{}, {8[T]}, {14[T], 15[T]}] Step with 8 Trace 10[T], 15[(-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0)], 8[(y <= 0)] Blocked [{}, {8[T]}, {14[T], 15[T]}, {}] Backtrack Trace 10[T], 15[(-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0)] Blocked [{}, {8[T]}, {8[y <= 0], 14[T], 15[T]}] Step with 8 Trace 10[T], 15[(-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0)], 8[(x <= 0)] Blocked [{}, {8[T]}, {8[y <= 0], 14[T], 15[T]}, {}] Backtrack Trace 10[T], 15[(-1+n >= 0 /\ 1-n+x > 0 /\ 1-n+y > 0)] Blocked [{}, {8[T]}, {8[(y <= 0 /\ x <= 0)], 14[T], 15[T]}] Backtrack Trace 10[T] Blocked [{}, {8[T], 15[T]}] Step with 14 Trace 10[T], 14[(y > 0 /\ x > 0)] Blocked [{}, {8[T], 15[T]}, {}] Covered Trace 10[T] Blocked [{}, {8[T], 14[T], 15[T]}] Backtrack Trace Blocked [{10[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b