0.03/0.11 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.03/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.32 % Computer : n018.cluster.edu 0.12/0.32 % Model : x86_64 x86_64 0.12/0.32 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.12/0.32 % Memory : 8042.1875MB 0.12/0.32 % OS : Linux 3.10.0-693.el7.x86_64 0.12/0.32 % CPULimit : 180 0.12/0.32 % DateTime : Thu Aug 29 12:13:51 EDT 2019 0.12/0.33 % CPUTime : 0.17/0.50 % SZS status Theorem 0.17/0.50 0.17/0.50 % SZS output start Proof 0.17/0.50 Take the following subset of the input axioms: 0.17/0.50 fof(additive_associativity, axiom, ![A, B, C]: addition(addition(A, B), C)=addition(A, addition(B, C))). 0.17/0.50 fof(additive_commutativity, axiom, ![A, B]: addition(A, B)=addition(B, A)). 0.17/0.50 fof(distributivity2, axiom, ![A, B, C]: multiplication(addition(A, B), C)=addition(multiplication(A, C), multiplication(B, C))). 0.17/0.50 fof(goals, conjecture, ![X0]: strong_iteration(one)=strong_iteration(star(X0))). 0.17/0.50 fof(idempotence, axiom, ![A]: A=addition(A, A)). 0.17/0.50 fof(infty_coinduction, axiom, ![A, B, C]: (leq(C, addition(multiplication(A, C), B)) => leq(C, multiplication(strong_iteration(A), B)))). 0.17/0.50 fof(infty_unfold1, axiom, ![A]: strong_iteration(A)=addition(multiplication(A, strong_iteration(A)), one)). 0.17/0.50 fof(multiplicative_left_identity, axiom, ![A]: A=multiplication(one, A)). 0.17/0.50 fof(multiplicative_right_identity, axiom, ![A]: multiplication(A, one)=A). 0.17/0.50 fof(order, axiom, ![A, B]: (addition(A, B)=B <=> leq(A, B))). 0.17/0.50 fof(star_unfold2, axiom, ![A]: star(A)=addition(one, multiplication(star(A), A))). 0.17/0.50 0.17/0.50 Now clausify the problem and encode Horn clauses using encoding 3 of 0.17/0.50 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.17/0.50 We repeatedly replace C & s=t => u=v by the two clauses: 0.17/0.50 fresh(y, y, x1...xn) = u 0.17/0.50 C => fresh(s, t, x1...xn) = v 0.17/0.50 where fresh is a fresh function symbol and x1..xn are the free 0.17/0.50 variables of u and v. 0.17/0.50 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.17/0.50 input problem has no model of domain size 1). 0.17/0.50 0.17/0.50 The encoding turns the above axioms into the following unit equations and goals: 0.17/0.50 0.17/0.50 Axiom 1 (infty_coinduction): fresh4(X, X, Y, Z, W) = true. 0.17/0.50 Axiom 2 (order): fresh5(X, X, Y, Z) = true. 0.17/0.50 Axiom 3 (order_1): fresh(X, X, Y, Z) = Z. 0.17/0.50 Axiom 4 (idempotence): X = addition(X, X). 0.17/0.50 Axiom 5 (star_unfold2): star(X) = addition(one, multiplication(star(X), X)). 0.17/0.50 Axiom 6 (infty_unfold1): strong_iteration(X) = addition(multiplication(X, strong_iteration(X)), one). 0.17/0.50 Axiom 7 (additive_associativity): addition(addition(X, Y), Z) = addition(X, addition(Y, Z)). 0.17/0.50 Axiom 8 (order_1): fresh(leq(X, Y), true, X, Y) = addition(X, Y). 0.17/0.50 Axiom 9 (order): fresh5(addition(X, Y), Y, X, Y) = leq(X, Y). 0.17/0.50 Axiom 10 (distributivity2): multiplication(addition(X, Y), Z) = addition(multiplication(X, Z), multiplication(Y, Z)). 0.17/0.50 Axiom 11 (multiplicative_left_identity): X = multiplication(one, X). 0.17/0.50 Axiom 12 (multiplicative_right_identity): multiplication(X, one) = X. 0.17/0.50 Axiom 13 (additive_commutativity): addition(X, Y) = addition(Y, X). 0.17/0.50 Axiom 14 (infty_coinduction): fresh4(leq(X, addition(multiplication(Y, X), Z)), true, Y, Z, X) = leq(X, multiplication(strong_iteration(Y), Z)). 0.17/0.50 0.17/0.50 Lemma 15: addition(one, multiplication(X, strong_iteration(X))) = strong_iteration(X). 0.17/0.50 Proof: 0.17/0.50 addition(one, multiplication(X, strong_iteration(X))) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 addition(multiplication(X, strong_iteration(X)), one) 0.17/0.50 = { by axiom 6 (infty_unfold1) } 0.17/0.50 strong_iteration(X) 0.17/0.50 0.17/0.50 Lemma 16: addition(X, addition(X, Y)) = addition(X, Y). 0.17/0.50 Proof: 0.17/0.50 addition(X, addition(X, Y)) 0.17/0.50 = { by axiom 7 (additive_associativity) } 0.17/0.50 addition(addition(X, X), Y) 0.17/0.50 = { by axiom 4 (idempotence) } 0.17/0.50 addition(X, Y) 0.17/0.50 0.17/0.50 Lemma 17: leq(X, multiplication(strong_iteration(addition(Y, one)), Z)) = true. 0.17/0.50 Proof: 0.17/0.50 leq(X, multiplication(strong_iteration(addition(Y, one)), Z)) 0.17/0.50 = { by axiom 14 (infty_coinduction) } 0.17/0.50 fresh4(leq(X, addition(multiplication(addition(Y, one), X), Z)), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 fresh4(leq(X, addition(multiplication(addition(one, Y), X), Z)), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 10 (distributivity2) } 0.17/0.50 fresh4(leq(X, addition(addition(multiplication(one, X), multiplication(Y, X)), Z)), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 11 (multiplicative_left_identity) } 0.17/0.50 fresh4(leq(X, addition(addition(X, multiplication(Y, X)), Z)), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 7 (additive_associativity) } 0.17/0.50 fresh4(leq(X, addition(X, addition(multiplication(Y, X), Z))), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 fresh4(leq(X, addition(X, addition(Z, multiplication(Y, X)))), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 9 (order) } 0.17/0.50 fresh4(fresh5(addition(X, addition(X, addition(Z, multiplication(Y, X)))), addition(X, addition(Z, multiplication(Y, X))), X, addition(X, addition(Z, multiplication(Y, X)))), true, addition(Y, one), Z, X) 0.17/0.50 = { by lemma 16 } 0.17/0.50 fresh4(fresh5(addition(X, addition(Z, multiplication(Y, X))), addition(X, addition(Z, multiplication(Y, X))), X, addition(X, addition(Z, multiplication(Y, X)))), true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 2 (order) } 0.17/0.50 fresh4(true, true, addition(Y, one), Z, X) 0.17/0.50 = { by axiom 1 (infty_coinduction) } 0.17/0.50 true 0.17/0.50 0.17/0.50 Goal 1 (goals): strong_iteration(one) = strong_iteration(star(sK1_goals_X0)). 0.17/0.50 Proof: 0.17/0.50 strong_iteration(one) 0.17/0.50 = { by axiom 3 (order_1) } 0.17/0.50 fresh(true, true, strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)) 0.17/0.50 = { by lemma 17 } 0.17/0.50 fresh(leq(strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), multiplication(strong_iteration(addition(one, one)), one)), true, strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)) 0.17/0.50 = { by axiom 4 (idempotence) } 0.17/0.50 fresh(leq(strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), multiplication(strong_iteration(one), one)), true, strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)) 0.17/0.50 = { by axiom 12 (multiplicative_right_identity) } 0.17/0.50 fresh(leq(strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)), true, strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)) 0.17/0.50 = { by axiom 8 (order_1) } 0.17/0.50 addition(strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), strong_iteration(one)) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 addition(strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))) 0.17/0.50 = { by axiom 6 (infty_unfold1) } 0.17/0.50 addition(addition(multiplication(one, strong_iteration(one)), one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))) 0.17/0.50 = { by axiom 11 (multiplicative_left_identity) } 0.17/0.50 addition(addition(strong_iteration(one), one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 addition(addition(one, strong_iteration(one)), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))) 0.17/0.50 = { by axiom 7 (additive_associativity) } 0.17/0.50 addition(one, addition(strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)))) 0.17/0.50 = { by axiom 8 (order_1) } 0.17/0.50 addition(one, fresh(leq(strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))), true, strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)))) 0.17/0.50 = { by axiom 12 (multiplicative_right_identity) } 0.17/0.50 addition(one, fresh(leq(strong_iteration(one), multiplication(strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)), one)), true, strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)))) 0.17/0.50 = { by lemma 17 } 0.17/0.50 addition(one, fresh(true, true, strong_iteration(one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)))) 0.17/0.50 = { by axiom 3 (order_1) } 0.17/0.50 addition(one, strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))) 0.17/0.50 = { by lemma 15 } 0.17/0.50 addition(one, addition(one, multiplication(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one))))) 0.17/0.50 = { by lemma 16 } 0.17/0.50 addition(one, multiplication(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one), strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)))) 0.17/0.50 = { by lemma 15 } 0.17/0.50 strong_iteration(addition(multiplication(star(sK1_goals_X0), sK1_goals_X0), one)) 0.17/0.50 = { by axiom 13 (additive_commutativity) } 0.17/0.50 strong_iteration(addition(one, multiplication(star(sK1_goals_X0), sK1_goals_X0))) 0.17/0.50 = { by axiom 5 (star_unfold2) } 0.17/0.50 strong_iteration(star(sK1_goals_X0)) 0.17/0.50 % SZS output end Proof 0.17/0.50 0.17/0.50 RESULT: Theorem (the conjecture is true). 0.17/0.51 EOF