unknown Initial ITS Start location: l3 Program variables: x^0 y^0 0: l0 -> l1 : x^0'=x^post1, y^0'=y^post1, (1+x^0-y^0 <= 0 /\ 1-x^0+y^0 <= 0 /\ -x^post1+x^0 == 0 /\ -y^post1+y^0 == 0), cost: 1 1: l1 -> l0 : x^0'=x^post2, y^0'=y^post2, (-y^post2+y^0 == 0 /\ x^0-x^post2 == 0), cost: 1 2: l2 -> l0 : x^0'=x^post3, y^0'=y^post3, (-x^post3+x^0 == 0 /\ -y^post3+y^0 == 0), cost: 1 3: l3 -> l2 : x^0'=x^post4, y^0'=y^post4, (-x^post4+x^0 == 0 /\ -y^post4+y^0 == 0), cost: 1 Chained Linear Paths Start location: l3 Program variables: x^0 y^0 4: l3 -> l0 : x^0'=x^post3, y^0'=y^post3, (-x^post4+x^0 == 0 /\ -y^post4+y^0 == 0 /\ y^post4-y^post3 == 0 /\ x^post4-x^post3 == 0), cost: 1 Eliminating location l2 by chaining: Applied chaining First rule: l3 -> l2 : x^0'=x^post4, y^0'=y^post4, (-x^post4+x^0 == 0 /\ -y^post4+y^0 == 0), cost: 1 Second rule: l2 -> l0 : x^0'=x^post3, y^0'=y^post3, (-x^post3+x^0 == 0 /\ -y^post3+y^0 == 0), cost: 1 New rule: l3 -> l0 : x^0'=x^post3, y^0'=y^post3, (-x^post4+x^0 == 0 /\ -y^post4+y^0 == 0 /\ y^post4-y^post3 == 0 /\ x^post4-x^post3 == 0), cost: 1 Applied deletion Removed the following rules: 2 3 Eliminating location l1 by chaining: Applied deletion Removed the following rules: 0 1 Simplified Transitions Start location: l3 Program variables: 5: l3 -> l0 : T, cost: 1 Propagated Equalities Original rule: l3 -> l0 : x^0'=x^post3, y^0'=y^post3, (-x^post4+x^0 == 0 /\ -y^post4+y^0 == 0 /\ y^post4-y^post3 == 0 /\ x^post4-x^post3 == 0), cost: 1 New rule: l3 -> l0 : x^0'=x^post4, y^0'=y^post4, (0 == 0 /\ -x^post4+x^0 == 0 /\ -y^post4+y^0 == 0), cost: 1 propagated equality y^post3 = y^post4 propagated equality x^post3 = x^post4 Propagated Equalities Original rule: l3 -> l0 : x^0'=x^post4, y^0'=y^post4, (0 == 0 /\ -x^post4+x^0 == 0 /\ -y^post4+y^0 == 0), cost: 1 New rule: l3 -> l0 : x^0'=x^0, y^0'=y^0, 0 == 0, cost: 1 propagated equality x^post4 = x^0 propagated equality y^post4 = y^0 Simplified Guard Original rule: l3 -> l0 : x^0'=x^0, y^0'=y^0, 0 == 0, cost: 1 New rule: l3 -> l0 : x^0'=x^0, y^0'=y^0, T, cost: 1 Removed Trivial Updates Original rule: l3 -> l0 : x^0'=x^0, y^0'=y^0, T, cost: 1 New rule: l3 -> l0 : T, cost: 1 Step with 5 Trace 5[T] Blocked [{}, {}] Backtrack Trace Blocked [{5[T]}] Accept unknown Build SHA: a05f16bf13df659c382799650051f91bf6828c7b