NO Initial ITS Start location: l8 Program variables: tmp2^0 x^0 0: l0 -> l1 : tmp2^0'=tmp2^post1, x^0'=x^post1, (x^0-x^post1 == 0 /\ -tmp2^post1+tmp2^0 == 0), cost: 1 4: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^post5, (0 == 0 /\ x^0-x^post5 == 0), cost: 1 1: l2 -> l3 : tmp2^0'=tmp2^post2, x^0'=x^post2, (-tmp2^0 <= 0 /\ tmp2^0 <= 0 /\ x^1 == 0 /\ -tmp2^post2+tmp2^0 == 0 /\ -1+x^post2 == 0), cost: 1 2: l2 -> l0 : tmp2^0'=tmp2^post3, x^0'=x^post3, (tmp2^0-tmp2^post3 == 0 /\ 1-tmp2^0 <= 0 /\ -x^post3+x^0 == 0), cost: 1 3: l2 -> l0 : tmp2^0'=tmp2^post4, x^0'=x^post4, (1+tmp2^0 <= 0 /\ x^0-x^post4 == 0 /\ -tmp2^post4+tmp2^0 == 0), cost: 1 5: l3 -> l4 : tmp2^0'=tmp2^post6, x^0'=x^post6, (-x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 6: l4 -> l3 : tmp2^0'=tmp2^post7, x^0'=x^post7, (x^0-x^post7 == 0 /\ -tmp2^post7+tmp2^0 == 0), cost: 1 7: l5 -> l6 : tmp2^0'=tmp2^post8, x^0'=x^post8, (tmp2^0-tmp2^post8 == 0 /\ -x^post8+x^0 == 0), cost: 1 8: l7 -> l1 : tmp2^0'=tmp2^post9, x^0'=x^post9, (-tmp2^post9+tmp2^0 == 0 /\ -1+x^post9 == 0), cost: 1 9: l8 -> l7 : tmp2^0'=tmp2^post10, x^0'=x^post10, (x^0-x^post10 == 0 /\ -tmp2^post10+tmp2^0 == 0), cost: 1 Chained Linear Paths Start location: l8 Program variables: tmp2^0 x^0 0: l0 -> l1 : tmp2^0'=tmp2^post1, x^0'=x^post1, (x^0-x^post1 == 0 /\ -tmp2^post1+tmp2^0 == 0), cost: 1 4: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^post5, (0 == 0 /\ x^0-x^post5 == 0), cost: 1 1: l2 -> l3 : tmp2^0'=tmp2^post2, x^0'=x^post2, (-tmp2^0 <= 0 /\ tmp2^0 <= 0 /\ x^1 == 0 /\ -tmp2^post2+tmp2^0 == 0 /\ -1+x^post2 == 0), cost: 1 2: l2 -> l0 : tmp2^0'=tmp2^post3, x^0'=x^post3, (tmp2^0-tmp2^post3 == 0 /\ 1-tmp2^0 <= 0 /\ -x^post3+x^0 == 0), cost: 1 3: l2 -> l0 : tmp2^0'=tmp2^post4, x^0'=x^post4, (1+tmp2^0 <= 0 /\ x^0-x^post4 == 0 /\ -tmp2^post4+tmp2^0 == 0), cost: 1 11: l3 -> l3 : tmp2^0'=tmp2^post7, x^0'=x^post7, (x^post6-x^post7 == 0 /\ -tmp2^post7+tmp2^post6 == 0 /\ -x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 7: l5 -> l6 : tmp2^0'=tmp2^post8, x^0'=x^post8, (tmp2^0-tmp2^post8 == 0 /\ -x^post8+x^0 == 0), cost: 1 10: l8 -> l1 : tmp2^0'=tmp2^post9, x^0'=x^post9, (x^0-x^post10 == 0 /\ tmp2^post10-tmp2^post9 == 0 /\ -tmp2^post10+tmp2^0 == 0 /\ -1+x^post9 == 0), cost: 1 Eliminating location l7 by chaining: Applied chaining First rule: l8 -> l7 : tmp2^0'=tmp2^post10, x^0'=x^post10, (x^0-x^post10 == 0 /\ -tmp2^post10+tmp2^0 == 0), cost: 1 Second rule: l7 -> l1 : tmp2^0'=tmp2^post9, x^0'=x^post9, (-tmp2^post9+tmp2^0 == 0 /\ -1+x^post9 == 0), cost: 1 New rule: l8 -> l1 : tmp2^0'=tmp2^post9, x^0'=x^post9, (x^0-x^post10 == 0 /\ tmp2^post10-tmp2^post9 == 0 /\ -tmp2^post10+tmp2^0 == 0 /\ -1+x^post9 == 0), cost: 1 Applied deletion Removed the following rules: 8 9 Eliminating location l4 by chaining: Applied chaining First rule: l3 -> l4 : tmp2^0'=tmp2^post6, x^0'=x^post6, (-x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 Second rule: l4 -> l3 : tmp2^0'=tmp2^post7, x^0'=x^post7, (x^0-x^post7 == 0 /\ -tmp2^post7+tmp2^0 == 0), cost: 1 New rule: l3 -> l3 : tmp2^0'=tmp2^post7, x^0'=x^post7, (x^post6-x^post7 == 0 /\ -tmp2^post7+tmp2^post6 == 0 /\ -x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 Applied deletion Removed the following rules: 5 6 Simplified Transitions Start location: l8 Program variables: tmp2^0 x^0 12: l0 -> l1 : T, cost: 1 16: l1 -> l2 : tmp2^0'=tmp2^post5, T, cost: 1 13: l2 -> l3 : x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 14: l2 -> l0 : 1-tmp2^0 <= 0, cost: 1 15: l2 -> l0 : 1+tmp2^0 <= 0, cost: 1 19: l3 -> l3 : T, cost: 1 17: l5 -> l6 : T, cost: 1 18: l8 -> l1 : x^0'=1, T, cost: 1 Propagated Equalities Original rule: l0 -> l1 : tmp2^0'=tmp2^post1, x^0'=x^post1, (x^0-x^post1 == 0 /\ -tmp2^post1+tmp2^0 == 0), cost: 1 New rule: l0 -> l1 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 propagated equality x^post1 = x^0 propagated equality tmp2^post1 = tmp2^0 Simplified Guard Original rule: l0 -> l1 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 New rule: l0 -> l1 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 Removed Trivial Updates Original rule: l0 -> l1 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 New rule: l0 -> l1 : T, cost: 1 made implied equalities explicit Original rule: l2 -> l3 : tmp2^0'=tmp2^post2, x^0'=x^post2, (-tmp2^0 <= 0 /\ tmp2^0 <= 0 /\ x^1 == 0 /\ -tmp2^post2+tmp2^0 == 0 /\ -1+x^post2 == 0), cost: 1 New rule: l2 -> l3 : tmp2^0'=tmp2^post2, x^0'=x^post2, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0 /\ x^1 == 0 /\ -tmp2^post2+tmp2^0 == 0 /\ -1+x^post2 == 0), cost: 1 Propagated Equalities Original rule: l2 -> l3 : tmp2^0'=tmp2^post2, x^0'=x^post2, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0 /\ x^1 == 0 /\ -tmp2^post2+tmp2^0 == 0 /\ -1+x^post2 == 0), cost: 1 New rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (0 == 0 /\ -tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0 /\ x^1 == 0), cost: 1 propagated equality tmp2^post2 = tmp2^0 propagated equality x^post2 = 1 Propagated Equalities Original rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (0 == 0 /\ -tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0 /\ x^1 == 0), cost: 1 New rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (0 == 0 /\ -tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 propagated equality x^1 = 0 Simplified Guard Original rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (0 == 0 /\ -tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 New rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 made implied equalities explicit Original rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 New rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 Removed Trivial Updates Original rule: l2 -> l3 : tmp2^0'=tmp2^0, x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 New rule: l2 -> l3 : x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 Propagated Equalities Original rule: l2 -> l0 : tmp2^0'=tmp2^post3, x^0'=x^post3, (tmp2^0-tmp2^post3 == 0 /\ 1-tmp2^0 <= 0 /\ -x^post3+x^0 == 0), cost: 1 New rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, (0 == 0 /\ 1-tmp2^0 <= 0), cost: 1 propagated equality tmp2^post3 = tmp2^0 propagated equality x^post3 = x^0 Simplified Guard Original rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, (0 == 0 /\ 1-tmp2^0 <= 0), cost: 1 New rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, 1-tmp2^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, 1-tmp2^0 <= 0, cost: 1 New rule: l2 -> l0 : 1-tmp2^0 <= 0, cost: 1 Propagated Equalities Original rule: l2 -> l0 : tmp2^0'=tmp2^post4, x^0'=x^post4, (1+tmp2^0 <= 0 /\ x^0-x^post4 == 0 /\ -tmp2^post4+tmp2^0 == 0), cost: 1 New rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, (0 == 0 /\ 1+tmp2^0 <= 0), cost: 1 propagated equality x^post4 = x^0 propagated equality tmp2^post4 = tmp2^0 Simplified Guard Original rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, (0 == 0 /\ 1+tmp2^0 <= 0), cost: 1 New rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, 1+tmp2^0 <= 0, cost: 1 Removed Trivial Updates Original rule: l2 -> l0 : tmp2^0'=tmp2^0, x^0'=x^0, 1+tmp2^0 <= 0, cost: 1 New rule: l2 -> l0 : 1+tmp2^0 <= 0, cost: 1 Propagated Equalities Original rule: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^post5, (0 == 0 /\ x^0-x^post5 == 0), cost: 1 New rule: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^0, 0 == 0, cost: 1 propagated equality x^post5 = x^0 Simplified Guard Original rule: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^0, 0 == 0, cost: 1 New rule: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^0, T, cost: 1 Removed Trivial Updates Original rule: l1 -> l2 : tmp2^0'=tmp2^post5, x^0'=x^0, T, cost: 1 New rule: l1 -> l2 : tmp2^0'=tmp2^post5, T, cost: 1 Propagated Equalities Original rule: l5 -> l6 : tmp2^0'=tmp2^post8, x^0'=x^post8, (tmp2^0-tmp2^post8 == 0 /\ -x^post8+x^0 == 0), cost: 1 New rule: l5 -> l6 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 propagated equality tmp2^post8 = tmp2^0 propagated equality x^post8 = x^0 Simplified Guard Original rule: l5 -> l6 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 New rule: l5 -> l6 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 Removed Trivial Updates Original rule: l5 -> l6 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 New rule: l5 -> l6 : T, cost: 1 Propagated Equalities Original rule: l8 -> l1 : tmp2^0'=tmp2^post9, x^0'=x^post9, (x^0-x^post10 == 0 /\ tmp2^post10-tmp2^post9 == 0 /\ -tmp2^post10+tmp2^0 == 0 /\ -1+x^post9 == 0), cost: 1 New rule: l8 -> l1 : tmp2^0'=tmp2^post10, x^0'=1, (0 == 0 /\ x^0-x^post10 == 0 /\ -tmp2^post10+tmp2^0 == 0), cost: 1 propagated equality tmp2^post9 = tmp2^post10 propagated equality x^post9 = 1 Propagated Equalities Original rule: l8 -> l1 : tmp2^0'=tmp2^post10, x^0'=1, (0 == 0 /\ x^0-x^post10 == 0 /\ -tmp2^post10+tmp2^0 == 0), cost: 1 New rule: l8 -> l1 : tmp2^0'=tmp2^0, x^0'=1, 0 == 0, cost: 1 propagated equality x^post10 = x^0 propagated equality tmp2^post10 = tmp2^0 Simplified Guard Original rule: l8 -> l1 : tmp2^0'=tmp2^0, x^0'=1, 0 == 0, cost: 1 New rule: l8 -> l1 : tmp2^0'=tmp2^0, x^0'=1, T, cost: 1 Removed Trivial Updates Original rule: l8 -> l1 : tmp2^0'=tmp2^0, x^0'=1, T, cost: 1 New rule: l8 -> l1 : x^0'=1, T, cost: 1 Propagated Equalities Original rule: l3 -> l3 : tmp2^0'=tmp2^post7, x^0'=x^post7, (x^post6-x^post7 == 0 /\ -tmp2^post7+tmp2^post6 == 0 /\ -x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 New rule: l3 -> l3 : tmp2^0'=tmp2^post6, x^0'=x^post6, (0 == 0 /\ -x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 propagated equality x^post7 = x^post6 propagated equality tmp2^post7 = tmp2^post6 Propagated Equalities Original rule: l3 -> l3 : tmp2^0'=tmp2^post6, x^0'=x^post6, (0 == 0 /\ -x^post6+x^0 == 0 /\ tmp2^0-tmp2^post6 == 0), cost: 1 New rule: l3 -> l3 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 propagated equality x^post6 = x^0 propagated equality tmp2^post6 = tmp2^0 Simplified Guard Original rule: l3 -> l3 : tmp2^0'=tmp2^0, x^0'=x^0, 0 == 0, cost: 1 New rule: l3 -> l3 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 Removed Trivial Updates Original rule: l3 -> l3 : tmp2^0'=tmp2^0, x^0'=x^0, T, cost: 1 New rule: l3 -> l3 : T, cost: 1 Step with 18 Trace 18[T] Blocked [{}, {}] Step with 16 Trace 18[T], 16[T] Blocked [{}, {}, {}] Step with 13 Trace 18[T], 16[T], 13[(-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0)] Blocked [{}, {}, {}, {}] Step with 19 Trace 18[T], 16[T], 13[(-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0)], 19[T] Blocked [{}, {}, {}, {}, {}] Nonterm Start location: l8 Program variables: tmp2^0 x^0 12: l0 -> l1 : T, cost: 1 16: l1 -> l2 : tmp2^0'=tmp2^post5, T, cost: 1 13: l2 -> l3 : x^0'=1, (-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0), cost: 1 14: l2 -> l0 : 1-tmp2^0 <= 0, cost: 1 15: l2 -> l0 : 1+tmp2^0 <= 0, cost: 1 19: l3 -> l3 : T, cost: 1 20: l3 -> LoAT_sink : -1+n >= 0, cost: NONTERM 17: l5 -> l6 : T, cost: 1 18: l8 -> l1 : x^0'=1, T, cost: 1 Certificate of Non-Termination Original rule: l3 -> l3 : T, cost: 1 New rule: l3 -> LoAT_sink : -1+n >= 0, cost: NONTERM Replacement map: {} Step with 20 Trace 18[T], 16[T], 13[(-tmp2^0 <= 0 /\ -tmp2^0 == 0 /\ tmp2^0 <= 0)], 20[-1+n >= 0] Blocked [{}, {}, {}, {}, {20[T]}] Refute Counterexample [ tmp2^0=0 x^0=1 ] 18 [ tmp2^0=0 x^0=1 ] 16 [ tmp2^0=0 x^0=1 ] 13 [ tmp2^0=0 x^0=x^0 ] 20 NO Build SHA: a05f16bf13df659c382799650051f91bf6828c7b