unknown Initial ITS Start location: l4 Program variables: x^0 0: l0 -> l2 : x^0'=x^post1, 1+x^post1-x^0 == 0, cost: 1 1: l2 -> l1 : x^0'=x^post2, (-x^post2+x^0 == 0 /\ 1-x^0 <= 0), cost: 1 2: l2 -> l1 : x^0'=x^post3, (-x^post3+x^0 == 0 /\ 1+x^0 <= 0), cost: 1 3: l1 -> l0 : x^0'=x^post4, -x^post4+x^0 == 0, cost: 1 4: l3 -> l0 : x^0'=x^post5, (-x^post5+x^0 == 0 /\ 1-x^0 <= 0), cost: 1 5: l4 -> l3 : x^0'=x^post6, -x^post6+x^0 == 0, cost: 1 Chained Linear Paths Start location: l4 Program variables: x^0 0: l0 -> l2 : x^0'=x^post1, 1+x^post1-x^0 == 0, cost: 1 1: l2 -> l1 : x^0'=x^post2, (-x^post2+x^0 == 0 /\ 1-x^0 <= 0), cost: 1 2: l2 -> l1 : x^0'=x^post3, (-x^post3+x^0 == 0 /\ 1+x^0 <= 0), cost: 1 3: l1 -> l0 : x^0'=x^post4, -x^post4+x^0 == 0, cost: 1 6: l4 -> l0 : x^0'=x^post5, (-x^post6+x^0 == 0 /\ 1-x^post6 <= 0 /\ x^post6-x^post5 == 0), cost: 1 Eliminating location l3 by chaining: Applied chaining First rule: l4 -> l3 : x^0'=x^post6, -x^post6+x^0 == 0, cost: 1 Second rule: l3 -> l0 : x^0'=x^post5, (-x^post5+x^0 == 0 /\ 1-x^0 <= 0), cost: 1 New rule: l4 -> l0 : x^0'=x^post5, (-x^post6+x^0 == 0 /\ 1-x^post6 <= 0 /\ x^post6-x^post5 == 0), cost: 1 Applied deletion Removed the following rules: 4 5 Simplified Transitions Start location: l4 Program variables: x^0 7: l0 -> l2 : x^0'=-1+x^0, T, cost: 1 8: l2 -> l1 : 1-x^0 <= 0, cost: 1 9: l2 -> l1 : 1+x^0 <= 0, cost: 1 10: l1 -> l0 : T, cost: 1 11: l4 -> l0 : 1-x^0 <= 0, cost: 1 Propagated Equalities Original rule: l0 -> l2 : x^0'=x^post1, 1+x^post1-x^0 == 0, cost: 1 New rule: l0 -> l2 : x^0'=-1+x^0, 0 == 0, cost: 1 propagated equality x^post1 = -1+x^0 Simplified Guard Original rule: l0 -> l2 : x^0'=-1+x^0, 0 == 0, cost: 1 New rule: l0 -> l2 : x^0'=-1+x^0, T, cost: 1 Propagated Equalities Original rule: l2 -> l1 : x^0'=x^post2, (-x^post2+x^0 == 0 /\ 1-x^0 <= 0), cost: 1 New rule: l2 -> l1 : x^0'=x^0, (0 == 0 /\ 1-x^0 <= 0), cost: 1 propagated equality x^post2 = x^0 Simplified Guard Original rule: l2 -> l1 : x^0'=x^0, (0 == 0 /\ 1-x^0 <= 0), cost: 1 New rule: l2 -> l1 : x^0'=x^0, 1-x^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l2 -> l1 : x^0'=x^0, 1-x^0 <= 0, cost: 1 New rule: l2 -> l1 : 1-x^0 <= 0, cost: 1 Propagated Equalities Original rule: l2 -> l1 : x^0'=x^post3, (-x^post3+x^0 == 0 /\ 1+x^0 <= 0), cost: 1 New rule: l2 -> l1 : x^0'=x^0, (0 == 0 /\ 1+x^0 <= 0), cost: 1 propagated equality x^post3 = x^0 Simplified Guard Original rule: l2 -> l1 : x^0'=x^0, (0 == 0 /\ 1+x^0 <= 0), cost: 1 New rule: l2 -> l1 : x^0'=x^0, 1+x^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l2 -> l1 : x^0'=x^0, 1+x^0 <= 0, cost: 1 New rule: l2 -> l1 : 1+x^0 <= 0, cost: 1 Propagated Equalities Original rule: l1 -> l0 : x^0'=x^post4, -x^post4+x^0 == 0, cost: 1 New rule: l1 -> l0 : x^0'=x^0, 0 == 0, cost: 1 propagated equality x^post4 = x^0 Simplified Guard Original rule: l1 -> l0 : x^0'=x^0, 0 == 0, cost: 1 New rule: l1 -> l0 : x^0'=x^0, T, cost: 1 Removed Trivial Updates Original rule: l1 -> l0 : x^0'=x^0, T, cost: 1 New rule: l1 -> l0 : T, cost: 1 Propagated Equalities Original rule: l4 -> l0 : x^0'=x^post5, (-x^post6+x^0 == 0 /\ 1-x^post6 <= 0 /\ x^post6-x^post5 == 0), cost: 1 New rule: l4 -> l0 : x^0'=x^post6, (0 == 0 /\ -x^post6+x^0 == 0 /\ 1-x^post6 <= 0), cost: 1 propagated equality x^post5 = x^post6 Propagated Equalities Original rule: l4 -> l0 : x^0'=x^post6, (0 == 0 /\ -x^post6+x^0 == 0 /\ 1-x^post6 <= 0), cost: 1 New rule: l4 -> l0 : x^0'=x^0, (0 == 0 /\ 1-x^0 <= 0), cost: 1 propagated equality x^post6 = x^0 Simplified Guard Original rule: l4 -> l0 : x^0'=x^0, (0 == 0 /\ 1-x^0 <= 0), cost: 1 New rule: l4 -> l0 : x^0'=x^0, 1-x^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l4 -> l0 : x^0'=x^0, 1-x^0 <= 0, cost: 1 New rule: l4 -> l0 : 1-x^0 <= 0, cost: 1 Step with 11 Trace 11[(1-x^0 <= 0)] Blocked [{}, {}] Step with 7 Trace 11[(1-x^0 <= 0)], 7[T] Blocked [{}, {}, {}] Step with 8 Trace 11[(1-x^0 <= 0)], 7[T], 8[(1-x^0 <= 0)] Blocked [{}, {}, {}, {}] Step with 10 Trace 11[(1-x^0 <= 0)], 7[T], 8[(1-x^0 <= 0)], 10[T] Blocked [{}, {}, {}, {}, {}] Accelerate Start location: l4 Program variables: x^0 7: l0 -> l2 : x^0'=-1+x^0, T, cost: 1 12: l0 -> l0 : x^0'=-n+x^0, (-1-n+x^0 >= 0 /\ -1+n >= 0), cost: 1 8: l2 -> l1 : 1-x^0 <= 0, cost: 1 9: l2 -> l1 : 1+x^0 <= 0, cost: 1 10: l1 -> l0 : T, cost: 1 11: l4 -> l0 : 1-x^0 <= 0, cost: 1 Loop Acceleration Original rule: l0 -> l0 : x^0'=-1+x^0, 2-x^0 <= 0, cost: 1 New rule: l0 -> l0 : x^0'=-n+x^0, (-1-n+x^0 >= 0 /\ -1+n >= 0), cost: 1 -2+x^0 >= 0 [0]: montonic decrease yields -1-n+x^0 >= 0 -2+x^0 >= 0 [1]: eventual increase yields (-2+x^0 >= 0 /\ 1 <= 0) Replacement map: {-2+x^0 >= 0 -> -1-n+x^0 >= 0} Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)] Blocked [{}, {}, {12[T]}] Step with 7 Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)], 7[T] Blocked [{}, {}, {12[T]}, {}] Step with 8 Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)], 7[T], 8[(1-x^0 <= 0)] Blocked [{}, {}, {12[T]}, {}, {}] Step with 10 Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)], 7[T], 8[(1-x^0 <= 0)], 10[T] Blocked [{}, {}, {12[T]}, {}, {}, {}] Covered Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)], 7[T], 8[(1-x^0 <= 0)] Blocked [{}, {}, {12[T]}, {}, {10[T]}] Backtrack Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)], 7[T] Blocked [{}, {}, {12[T]}, {8[T]}] Backtrack Trace 11[(1-x^0 <= 0)], 12[(-1-n+x^0 >= 0 /\ -1+n >= 0)] Blocked [{}, {}, {7[T], 12[T]}] Backtrack Trace 11[(1-x^0 <= 0)] Blocked [{}, {12[T]}] Step with 7 Trace 11[(1-x^0 <= 0)], 7[T] Blocked [{}, {12[T]}, {}] Step with 8 Trace 11[(1-x^0 <= 0)], 7[T], 8[(1-x^0 <= 0)] Blocked [{}, {12[T]}, {}, {}] Step with 10 Trace 11[(1-x^0 <= 0)], 7[T], 8[(1-x^0 <= 0)], 10[T] Blocked [{}, {12[T]}, {}, {}, {}] Covered Trace 11[(1-x^0 <= 0)], 7[T], 8[(1-x^0 <= 0)] Blocked [{}, {12[T]}, {}, {10[T]}] Backtrack Trace 11[(1-x^0 <= 0)], 7[T] Blocked [{}, {12[T]}, {8[T]}] Backtrack Trace 11[(1-x^0 <= 0)] Blocked [{}, {7[T], 12[T]}] Backtrack Trace Blocked [{11[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b