NO Initial ITS Start location: l7 Program variables: i^0 j^0 0: l0 -> l1 : i^0'=i^post1, j^0'=j^post1, (-i^post1+i^0 == 0 /\ j^post1-i^0 == 0), cost: 1 1: l1 -> l2 : i^0'=i^post2, j^0'=j^post2, (-1+i^post2-i^0 == 0 /\ -j^post2+j^0 == 0), cost: 1 7: l2 -> l4 : i^0'=i^post8, j^0'=j^post8, (-i^post8+i^0 == 0 /\ j^0-j^post8 == 0), cost: 1 2: l3 -> l0 : i^0'=i^post3, j^0'=j^post3, (-i^post3+i^0 == 0 /\ 6-i^0 <= 0 /\ j^0-j^post3 == 0), cost: 1 3: l3 -> l0 : i^0'=i^post4, j^0'=j^post4, (-4+i^0 <= 0 /\ -j^post4+j^0 == 0 /\ -i^post4+i^0 == 0), cost: 1 4: l3 -> l1 : i^0'=i^post5, j^0'=j^post5, (0 == 0 /\ -5+i^0 <= 0 /\ 5-i^0 <= 0 /\ -j^post5+j^0 == 0), cost: 1 5: l4 -> l5 : i^0'=i^post6, j^0'=j^post6, (10-i^0 <= 0 /\ j^0-j^post6 == 0 /\ -i^post6+i^0 == 0), cost: 1 6: l4 -> l3 : i^0'=i^post7, j^0'=j^post7, (-9+i^0 <= 0 /\ -j^post7+j^0 == 0 /\ -i^post7+i^0 == 0), cost: 1 8: l6 -> l2 : i^0'=i^post9, j^0'=j^post9, (i^post9 == 0 /\ -j^post9+j^0 == 0), cost: 1 9: l7 -> l6 : i^0'=i^post10, j^0'=j^post10, (-i^post10+i^0 == 0 /\ -j^post10+j^0 == 0), cost: 1 Chained Linear Paths Start location: l7 Program variables: i^0 j^0 0: l0 -> l1 : i^0'=i^post1, j^0'=j^post1, (-i^post1+i^0 == 0 /\ j^post1-i^0 == 0), cost: 1 1: l1 -> l2 : i^0'=i^post2, j^0'=j^post2, (-1+i^post2-i^0 == 0 /\ -j^post2+j^0 == 0), cost: 1 7: l2 -> l4 : i^0'=i^post8, j^0'=j^post8, (-i^post8+i^0 == 0 /\ j^0-j^post8 == 0), cost: 1 2: l3 -> l0 : i^0'=i^post3, j^0'=j^post3, (-i^post3+i^0 == 0 /\ 6-i^0 <= 0 /\ j^0-j^post3 == 0), cost: 1 3: l3 -> l0 : i^0'=i^post4, j^0'=j^post4, (-4+i^0 <= 0 /\ -j^post4+j^0 == 0 /\ -i^post4+i^0 == 0), cost: 1 4: l3 -> l1 : i^0'=i^post5, j^0'=j^post5, (0 == 0 /\ -5+i^0 <= 0 /\ 5-i^0 <= 0 /\ -j^post5+j^0 == 0), cost: 1 5: l4 -> l5 : i^0'=i^post6, j^0'=j^post6, (10-i^0 <= 0 /\ j^0-j^post6 == 0 /\ -i^post6+i^0 == 0), cost: 1 6: l4 -> l3 : i^0'=i^post7, j^0'=j^post7, (-9+i^0 <= 0 /\ -j^post7+j^0 == 0 /\ -i^post7+i^0 == 0), cost: 1 10: l7 -> l2 : i^0'=i^post9, j^0'=j^post9, (i^post9 == 0 /\ -i^post10+i^0 == 0 /\ j^post10-j^post9 == 0 /\ -j^post10+j^0 == 0), cost: 1 Eliminating location l6 by chaining: Applied chaining First rule: l7 -> l6 : i^0'=i^post10, j^0'=j^post10, (-i^post10+i^0 == 0 /\ -j^post10+j^0 == 0), cost: 1 Second rule: l6 -> l2 : i^0'=i^post9, j^0'=j^post9, (i^post9 == 0 /\ -j^post9+j^0 == 0), cost: 1 New rule: l7 -> l2 : i^0'=i^post9, j^0'=j^post9, (i^post9 == 0 /\ -i^post10+i^0 == 0 /\ j^post10-j^post9 == 0 /\ -j^post10+j^0 == 0), cost: 1 Applied deletion Removed the following rules: 8 9 Simplified Transitions Start location: l7 Program variables: i^0 j^0 11: l0 -> l1 : j^0'=i^0, T, cost: 1 12: l1 -> l2 : i^0'=1+i^0, T, cost: 1 18: l2 -> l4 : T, cost: 1 13: l3 -> l0 : 6-i^0 <= 0, cost: 1 14: l3 -> l0 : -4+i^0 <= 0, cost: 1 15: l3 -> l1 : i^0'=i^post5, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 16: l4 -> l5 : 10-i^0 <= 0, cost: 1 17: l4 -> l3 : -9+i^0 <= 0, cost: 1 19: l7 -> l2 : i^0'=0, T, cost: 1 Propagated Equalities Original rule: l0 -> l1 : i^0'=i^post1, j^0'=j^post1, (-i^post1+i^0 == 0 /\ j^post1-i^0 == 0), cost: 1 New rule: l0 -> l1 : i^0'=i^0, j^0'=i^0, 0 == 0, cost: 1 propagated equality i^post1 = i^0 propagated equality j^post1 = i^0 Simplified Guard Original rule: l0 -> l1 : i^0'=i^0, j^0'=i^0, 0 == 0, cost: 1 New rule: l0 -> l1 : i^0'=i^0, j^0'=i^0, T, cost: 1 Removed Trivial Updates Original rule: l0 -> l1 : i^0'=i^0, j^0'=i^0, T, cost: 1 New rule: l0 -> l1 : j^0'=i^0, T, cost: 1 Propagated Equalities Original rule: l1 -> l2 : i^0'=i^post2, j^0'=j^post2, (-1+i^post2-i^0 == 0 /\ -j^post2+j^0 == 0), cost: 1 New rule: l1 -> l2 : i^0'=1+i^0, j^0'=j^0, 0 == 0, cost: 1 propagated equality i^post2 = 1+i^0 propagated equality j^post2 = j^0 Simplified Guard Original rule: l1 -> l2 : i^0'=1+i^0, j^0'=j^0, 0 == 0, cost: 1 New rule: l1 -> l2 : i^0'=1+i^0, j^0'=j^0, T, cost: 1 Removed Trivial Updates Original rule: l1 -> l2 : i^0'=1+i^0, j^0'=j^0, T, cost: 1 New rule: l1 -> l2 : i^0'=1+i^0, T, cost: 1 Propagated Equalities Original rule: l3 -> l0 : i^0'=i^post3, j^0'=j^post3, (-i^post3+i^0 == 0 /\ 6-i^0 <= 0 /\ j^0-j^post3 == 0), cost: 1 New rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ 6-i^0 <= 0), cost: 1 propagated equality i^post3 = i^0 propagated equality j^post3 = j^0 Simplified Guard Original rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ 6-i^0 <= 0), cost: 1 New rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, 6-i^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, 6-i^0 <= 0, cost: 1 New rule: l3 -> l0 : 6-i^0 <= 0, cost: 1 Propagated Equalities Original rule: l3 -> l0 : i^0'=i^post4, j^0'=j^post4, (-4+i^0 <= 0 /\ -j^post4+j^0 == 0 /\ -i^post4+i^0 == 0), cost: 1 New rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ -4+i^0 <= 0), cost: 1 propagated equality j^post4 = j^0 propagated equality i^post4 = i^0 Simplified Guard Original rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ -4+i^0 <= 0), cost: 1 New rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, -4+i^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l3 -> l0 : i^0'=i^0, j^0'=j^0, -4+i^0 <= 0, cost: 1 New rule: l3 -> l0 : -4+i^0 <= 0, cost: 1 made implied equalities explicit Original rule: l3 -> l1 : i^0'=i^post5, j^0'=j^post5, (0 == 0 /\ -5+i^0 <= 0 /\ 5-i^0 <= 0 /\ -j^post5+j^0 == 0), cost: 1 New rule: l3 -> l1 : i^0'=i^post5, j^0'=j^post5, (0 == 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0 /\ -j^post5+j^0 == 0), cost: 1 Propagated Equalities Original rule: l3 -> l1 : i^0'=i^post5, j^0'=j^post5, (0 == 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0 /\ -j^post5+j^0 == 0), cost: 1 New rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (0 == 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 propagated equality j^post5 = j^0 Simplified Guard Original rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (0 == 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 New rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 made implied equalities explicit Original rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 New rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 Removed Trivial Updates Original rule: l3 -> l1 : i^0'=i^post5, j^0'=j^0, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 New rule: l3 -> l1 : i^0'=i^post5, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 Propagated Equalities Original rule: l4 -> l5 : i^0'=i^post6, j^0'=j^post6, (10-i^0 <= 0 /\ j^0-j^post6 == 0 /\ -i^post6+i^0 == 0), cost: 1 New rule: l4 -> l5 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ 10-i^0 <= 0), cost: 1 propagated equality j^post6 = j^0 propagated equality i^post6 = i^0 Simplified Guard Original rule: l4 -> l5 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ 10-i^0 <= 0), cost: 1 New rule: l4 -> l5 : i^0'=i^0, j^0'=j^0, 10-i^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l4 -> l5 : i^0'=i^0, j^0'=j^0, 10-i^0 <= 0, cost: 1 New rule: l4 -> l5 : 10-i^0 <= 0, cost: 1 Propagated Equalities Original rule: l4 -> l3 : i^0'=i^post7, j^0'=j^post7, (-9+i^0 <= 0 /\ -j^post7+j^0 == 0 /\ -i^post7+i^0 == 0), cost: 1 New rule: l4 -> l3 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ -9+i^0 <= 0), cost: 1 propagated equality j^post7 = j^0 propagated equality i^post7 = i^0 Simplified Guard Original rule: l4 -> l3 : i^0'=i^0, j^0'=j^0, (0 == 0 /\ -9+i^0 <= 0), cost: 1 New rule: l4 -> l3 : i^0'=i^0, j^0'=j^0, -9+i^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l4 -> l3 : i^0'=i^0, j^0'=j^0, -9+i^0 <= 0, cost: 1 New rule: l4 -> l3 : -9+i^0 <= 0, cost: 1 Propagated Equalities Original rule: l2 -> l4 : i^0'=i^post8, j^0'=j^post8, (-i^post8+i^0 == 0 /\ j^0-j^post8 == 0), cost: 1 New rule: l2 -> l4 : i^0'=i^0, j^0'=j^0, 0 == 0, cost: 1 propagated equality i^post8 = i^0 propagated equality j^post8 = j^0 Simplified Guard Original rule: l2 -> l4 : i^0'=i^0, j^0'=j^0, 0 == 0, cost: 1 New rule: l2 -> l4 : i^0'=i^0, j^0'=j^0, T, cost: 1 Removed Trivial Updates Original rule: l2 -> l4 : i^0'=i^0, j^0'=j^0, T, cost: 1 New rule: l2 -> l4 : T, cost: 1 Propagated Equalities Original rule: l7 -> l2 : i^0'=i^post9, j^0'=j^post9, (i^post9 == 0 /\ -i^post10+i^0 == 0 /\ j^post10-j^post9 == 0 /\ -j^post10+j^0 == 0), cost: 1 New rule: l7 -> l2 : i^0'=0, j^0'=j^post10, (0 == 0 /\ -i^post10+i^0 == 0 /\ -j^post10+j^0 == 0), cost: 1 propagated equality i^post9 = 0 propagated equality j^post9 = j^post10 Propagated Equalities Original rule: l7 -> l2 : i^0'=0, j^0'=j^post10, (0 == 0 /\ -i^post10+i^0 == 0 /\ -j^post10+j^0 == 0), cost: 1 New rule: l7 -> l2 : i^0'=0, j^0'=j^0, 0 == 0, cost: 1 propagated equality i^post10 = i^0 propagated equality j^post10 = j^0 Simplified Guard Original rule: l7 -> l2 : i^0'=0, j^0'=j^0, 0 == 0, cost: 1 New rule: l7 -> l2 : i^0'=0, j^0'=j^0, T, cost: 1 Removed Trivial Updates Original rule: l7 -> l2 : i^0'=0, j^0'=j^0, T, cost: 1 New rule: l7 -> l2 : i^0'=0, T, cost: 1 Step with 19 Trace 19[T] Blocked [{}, {}] Step with 18 Trace 19[T], 18[T] Blocked [{}, {}, {}] Step with 17 Trace 19[T], 18[T], 17[(-9+i^0 <= 0)] Blocked [{}, {}, {16[T]}, {}] Step with 14 Trace 19[T], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)] Blocked [{}, {}, {16[T]}, {13[T]}, {}] Step with 11 Trace 19[T], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)], 11[T] Blocked [{}, {}, {16[T]}, {13[T]}, {}, {}] Step with 12 Trace 19[T], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)], 11[T], 12[T] Blocked [{}, {}, {16[T]}, {13[T]}, {}, {}, {}] Accelerate Start location: l7 Program variables: i^0 j^0 11: l0 -> l1 : j^0'=i^0, T, cost: 1 12: l1 -> l2 : i^0'=1+i^0, T, cost: 1 18: l2 -> l4 : T, cost: 1 20: l2 -> l2 : i^0'=n+i^0, j^0'=-1+n+i^0, (-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0), cost: 1 13: l3 -> l0 : 6-i^0 <= 0, cost: 1 14: l3 -> l0 : -4+i^0 <= 0, cost: 1 15: l3 -> l1 : i^0'=i^post5, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 16: l4 -> l5 : 10-i^0 <= 0, cost: 1 17: l4 -> l3 : -9+i^0 <= 0, cost: 1 19: l7 -> l2 : i^0'=0, T, cost: 1 Loop Acceleration Original rule: l2 -> l2 : i^0'=1+i^0, j^0'=i^0, (-9+i^0 <= 0 /\ -4+i^0 <= 0), cost: 1 New rule: l2 -> l2 : i^0'=n+i^0, j^0'=-1+n+i^0, (-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0), cost: 1 4-i^0 >= 0 [0]: montonic decrease yields 5-n-i^0 >= 0 4-i^0 >= 0 [1]: eventual increase yields (1 <= 0 /\ 4-i^0 >= 0) 9-i^0 >= 0 [0]: monotonic increase yields 9-i^0 >= 0, dependencies: 4-i^0 >= 0 Replacement map: {4-i^0 >= 0 -> 5-n-i^0 >= 0, 9-i^0 >= 0 -> 9-i^0 >= 0} Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)] Blocked [{}, {}, {20[T]}] Step with 18 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T] Blocked [{}, {}, {20[T]}, {}] Step with 17 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)] Blocked [{}, {}, {20[T]}, {}, {}] Step with 14 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)] Blocked [{}, {}, {20[T]}, {}, {}, {}] Step with 11 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)], 11[T] Blocked [{}, {}, {20[T]}, {}, {}, {}, {}] Step with 12 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)], 11[T], 12[T] Blocked [{}, {}, {20[T]}, {}, {}, {}, {}, {}] Covered Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)], 11[T] Blocked [{}, {}, {20[T]}, {}, {}, {}, {12[T]}] Backtrack Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 14[(-4+i^0 <= 0)] Blocked [{}, {}, {20[T]}, {}, {}, {11[T]}] Backtrack Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)] Blocked [{}, {}, {20[T]}, {}, {14[T]}] Step with 15 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 15[(-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0)] Blocked [{}, {}, {20[T]}, {}, {14[T]}, {}] Step with 12 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 18[T], 17[(-9+i^0 <= 0)], 15[(-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0)], 12[T] Blocked [{}, {}, {20[T]}, {}, {14[T]}, {}, {}] Nonterm Start location: l7 Program variables: i^0 j^0 11: l0 -> l1 : j^0'=i^0, T, cost: 1 12: l1 -> l2 : i^0'=1+i^0, T, cost: 1 18: l2 -> l4 : T, cost: 1 20: l2 -> l2 : i^0'=n+i^0, j^0'=-1+n+i^0, (-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0), cost: 1 21: l2 -> LoAT_sink : (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0 /\ -1-i^post51+i^0 <= 0), cost: NONTERM 22: l2 -> l2 : i^0'=5, (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0), cost: 1 13: l3 -> l0 : 6-i^0 <= 0, cost: 1 14: l3 -> l0 : -4+i^0 <= 0, cost: 1 15: l3 -> l1 : i^0'=i^post5, (-5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 16: l4 -> l5 : 10-i^0 <= 0, cost: 1 17: l4 -> l3 : -9+i^0 <= 0, cost: 1 19: l7 -> l2 : i^0'=0, T, cost: 1 Certificate of Non-Termination Original rule: l2 -> l2 : i^0'=1+i^post51, (-9+i^0 <= 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 New rule: l2 -> LoAT_sink : (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0 /\ -1-i^post51+i^0 <= 0), cost: NONTERM -5+i^0 >= 0 [0]: eventual decrease yields (-4+i^post51 >= 0 /\ -5+i^0 >= 0) -5+i^0 >= 0 [1]: eventual increase yields (-5+i^0 >= 0 /\ -1-i^post51+i^0 <= 0) 5-i^0 >= 0 [0]: eventual decrease yields (4-i^post51 >= 0 /\ 5-i^0 >= 0) 5-i^0 >= 0 [1]: eventual increase yields (5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0) 9-i^0 >= 0 [0]: montonic decrease yields 8-i^post51 >= 0, dependencies: 5-i^0 >= 0 9-i^0 >= 0 [1]: eventual increase yields (1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0) Replacement map: {-5+i^0 >= 0 -> (-5+i^0 >= 0 /\ -1-i^post51+i^0 <= 0), 5-i^0 >= 0 -> (5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0), 9-i^0 >= 0 -> (1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0)} Loop Acceleration Original rule: l2 -> l2 : i^0'=1+i^post51, (-9+i^0 <= 0 /\ -5+i^0 <= 0 /\ -5+i^0 == 0 /\ 5-i^0 <= 0), cost: 1 New rule: l2 -> l2 : i^0'=1+i^post51, (-4+i^post51 >= 0 /\ 4-i^post51 >= 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ -1+n2 >= 0 /\ 8-i^post51 >= 0), cost: 1 -5+i^0 >= 0 [0]: eventual decrease yields (-4+i^post51 >= 0 /\ -5+i^0 >= 0) -5+i^0 >= 0 [1]: eventual increase yields (-5+i^0 >= 0 /\ -1-i^post51+i^0 <= 0) 5-i^0 >= 0 [0]: eventual decrease yields (4-i^post51 >= 0 /\ 5-i^0 >= 0) 5-i^0 >= 0 [1]: eventual increase yields (5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0) 9-i^0 >= 0 [0]: montonic decrease yields 8-i^post51 >= 0, dependencies: 5-i^0 >= 0 9-i^0 >= 0 [1]: eventual increase yields (1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0) Replacement map: {-5+i^0 >= 0 -> (-4+i^post51 >= 0 /\ -5+i^0 >= 0), 5-i^0 >= 0 -> (4-i^post51 >= 0 /\ 5-i^0 >= 0), 9-i^0 >= 0 -> 8-i^post51 >= 0} made implied equalities explicit Original rule: l2 -> l2 : i^0'=1+i^post51, (-4+i^post51 >= 0 /\ 4-i^post51 >= 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ -1+n2 >= 0 /\ 8-i^post51 >= 0), cost: 1 New rule: l2 -> l2 : i^0'=1+i^post51, (-4+i^post51 >= 0 /\ 4-i^post51 >= 0 /\ 4-i^post51 == 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0 /\ 8-i^post51 >= 0), cost: 1 Propagated Equalities Original rule: l2 -> l2 : i^0'=1+i^post51, (-4+i^post51 >= 0 /\ 4-i^post51 >= 0 /\ 4-i^post51 == 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0 /\ 8-i^post51 >= 0), cost: 1 New rule: l2 -> l2 : i^0'=5, (0 >= 0 /\ 0 == 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0 /\ 4 >= 0), cost: 1 propagated equality i^post51 = 4 Simplified Guard Original rule: l2 -> l2 : i^0'=5, (0 >= 0 /\ 0 == 0 /\ -5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0 /\ 4 >= 0), cost: 1 New rule: l2 -> l2 : i^0'=5, (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0), cost: 1 Eliminated Temporary Variables via Transitive Closure Original rule: l2 -> l2 : i^0'=5, (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0 /\ -1+n2 >= 0), cost: 1 New rule: l2 -> l2 : i^0'=5, (-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 5-i^0 == 0), cost: 1 Step with 21 Trace 19[T], 20[(-1+n >= 0 /\ 5-n-i^0 >= 0 /\ 9-i^0 >= 0)], 21[(-5+i^0 >= 0 /\ 5-i^0 >= 0 /\ 1+i^post51-i^0 <= 0 /\ 9-i^0 >= 0 /\ -1-i^post51+i^0 <= 0)] Blocked [{}, {}, {20[T]}, {21[T]}] Refute Counterexample [ i^0=0 j^0=0 ] 19 [ i^0=5 j^0=4 ] 20 [ i^0=i^0 j^0=0 ] 21 NO Build SHA: a05f16bf13df659c382799650051f91bf6828c7b