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