unknown Initial ITS Start location: [1] Program variables: i j n t 0: [1] -> [2] : n'=nondet, T, cost: 1 1: [2] -> [3] : i'=0, T, cost: 1 2: [3] -> [4] : j'=1, T, cost: 1 3: [4] -> [5] : t'=0, T, cost: 1 4: [5] -> [6] : (j-n < 0 \/ j-n > 0), cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 5: [6] -> [7] : t'=i+j, T, cost: 1 6: [7] -> [8] : i'=j, T, cost: 1 7: [8] -> [9] : j'=t, T, cost: 1 8: [9] -> [5] : T, cost: 1 Chained Linear Paths Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Eliminating location [2] by chaining: Applied chaining First rule: [1] -> [2] : n'=nondet, T, cost: 1 Second rule: [2] -> [3] : i'=0, T, cost: 1 New rule: [1] -> [3] : i'=0, n'=nondet, T, cost: 1 Applied deletion Removed the following rules: 0 1 Eliminating location [3] by chaining: Applied chaining First rule: [1] -> [3] : i'=0, n'=nondet, T, cost: 1 Second rule: [3] -> [4] : j'=1, T, cost: 1 New rule: [1] -> [4] : i'=0, j'=1, n'=nondet, T, cost: 1 Applied deletion Removed the following rules: 2 10 Eliminating location [4] by chaining: Applied chaining First rule: [1] -> [4] : i'=0, j'=1, n'=nondet, T, cost: 1 Second rule: [4] -> [5] : t'=0, T, cost: 1 New rule: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 Applied deletion Removed the following rules: 3 11 Eliminating location [6] by chaining: Applied chaining First rule: [5] -> [6] : (j-n < 0 \/ j-n > 0), cost: 1 Second rule: [6] -> [7] : t'=i+j, T, cost: 1 New rule: [5] -> [7] : t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Applied deletion Removed the following rules: 4 5 Eliminating location [7] by chaining: Applied chaining First rule: [5] -> [7] : t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Second rule: [7] -> [8] : i'=j, T, cost: 1 New rule: [5] -> [8] : i'=j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Applied deletion Removed the following rules: 6 13 Eliminating location [8] by chaining: Applied chaining First rule: [5] -> [8] : i'=j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Second rule: [8] -> [9] : j'=t, T, cost: 1 New rule: [5] -> [9] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Applied deletion Removed the following rules: 7 14 Eliminating location [9] by chaining: Applied chaining First rule: [5] -> [9] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Second rule: [9] -> [5] : T, cost: 1 New rule: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 Applied deletion Removed the following rules: 8 15 Unrolled Loops Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 17: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 Unrolling Original rule: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 New rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 Step with 12 Trace 12[T] Blocked [{}, {}] Step with 9 Trace 12[T], 9[(j-n <= 0 /\ j-n >= 0)] Blocked [{}, {}, {}] Backtrack Trace 12[T] Blocked [{}, {9[T]}] Step with 16 Trace 12[T], 16[(j-n < 0)] Blocked [{}, {9[T]}, {}] Accelerate and Drop Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 17: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 18: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM unrolling Original rule: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0), cost: 1 New rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n < 0 /\ j-n < 0), cost: 1 Certificate of Non-Termination Original rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n < 0 /\ j-n < 0), cost: 1 New rule: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM -i-j+n > 0 [0]: fixpoint yields (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j == 0) -j+n > 0 [0]: fixpoint yields (0 == 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0) Replacement map: {-i-j+n > 0 -> (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j == 0), -j+n > 0 -> (0 == 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0)} Trace 12[T] Blocked [{}, {9[T], 16[j-n < 0]}] Step with 16 Trace 12[T], 16[(j-n > 0)] Blocked [{}, {9[T], 16[j-n < 0]}, {}] Accelerate and Drop Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 17: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 18: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM 19: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM unrolling Original rule: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n > 0), cost: 1 New rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n > 0 /\ j-n > 0), cost: 1 Certificate of Non-Termination Original rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n > 0 /\ j-n > 0), cost: 1 New rule: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM i+j-n > 0 [0]: fixpoint yields (0 == 0 /\ i+j-n > 0 /\ -i-j == 0 /\ -j == 0) j-n > 0 [0]: fixpoint yields (0 == 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0) Replacement map: {i+j-n > 0 -> (0 == 0 /\ i+j-n > 0 /\ -i-j == 0 /\ -j == 0), j-n > 0 -> (0 == 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0)} Trace 12[T] Blocked [{}, {9[T], 16[(j-n < 0 /\ j-n > 0)]}] Step with 17 Trace 12[T], 17[(i+j-n < 0 /\ j-n < 0)] Blocked [{}, {9[T], 16[T]}, {}] Accelerate and Drop Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 17: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 18: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM 19: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM 20: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM Certificate of Non-Termination Original rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n < 0 /\ j-n < 0), cost: 1 New rule: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM -i-j+n > 0 [0]: fixpoint yields (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j == 0) -j+n > 0 [0]: fixpoint yields (0 == 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0) Replacement map: {-i-j+n > 0 -> (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j == 0), -j+n > 0 -> (0 == 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0)} Trace 12[T] Blocked [{}, {9[T], 16[T], 17[(i+j-n < 0 /\ j-n < 0)]}] Step with 17 Trace 12[T], 17[(i+j-n > 0 /\ j-n > 0)] Blocked [{}, {9[T], 16[T], 17[(i+j-n < 0 /\ j-n < 0)]}, {}] Accelerate and Drop Start location: [1] Program variables: i j n t 12: [1] -> [5] : i'=0, j'=1, n'=nondet, t'=0, T, cost: 1 9: [5] -> [10] : (j-n <= 0 /\ j-n >= 0), cost: 1 16: [5] -> [5] : i'=j, j'=i+j, t'=i+j, (j-n < 0 \/ j-n > 0), cost: 1 17: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, ((j-n < 0 \/ j-n > 0) /\ (i+j-n < 0 \/ i+j-n > 0)), cost: 1 18: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM 19: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM 20: [5] -> LoAT_sink : (0 == 0 /\ -i-j+n > 0 /\ -i-j == 0 /\ -j+n > 0 /\ -j == 0), cost: NONTERM 21: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM Certificate of Non-Termination Original rule: [5] -> [5] : i'=i+j, j'=i+2*j, t'=i+2*j, (i+j-n > 0 /\ j-n > 0), cost: 1 New rule: [5] -> LoAT_sink : (0 == 0 /\ i+j-n > 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0), cost: NONTERM i+j-n > 0 [0]: fixpoint yields (0 == 0 /\ i+j-n > 0 /\ -i-j == 0 /\ -j == 0) j-n > 0 [0]: fixpoint yields (0 == 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0) Replacement map: {i+j-n > 0 -> (0 == 0 /\ i+j-n > 0 /\ -i-j == 0 /\ -j == 0), j-n > 0 -> (0 == 0 /\ j-n > 0 /\ -i-j == 0 /\ -j == 0)} Trace 12[T] Blocked [{}, {9[T], 16[T], 17[(i+j-n < 0 /\ i+j-n > 0 /\ j-n < 0 /\ j-n > 0)]}] Backtrack Trace Blocked [{12[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b