0.09/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.09/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.13/0.33 % Computer : n006.cluster.edu 0.13/0.33 % Model : x86_64 x86_64 0.13/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.13/0.33 % Memory : 8042.1875MB 0.13/0.33 % OS : Linux 3.10.0-693.el7.x86_64 0.13/0.33 % CPULimit : 180 0.13/0.33 % DateTime : Thu Aug 29 10:09:39 EDT 2019 0.13/0.33 % CPUTime : 0.79/1.01 % SZS status Unsatisfiable 0.79/1.01 0.79/1.01 % SZS output start Proof 0.79/1.01 Take the following subset of the input axioms: 0.88/1.03 fof(absorption1, axiom, ![X, Y]: meet(X, join(X, Y))=X). 0.88/1.03 fof(absorption2, axiom, ![X, Y]: X=join(X, meet(X, Y))). 0.88/1.03 fof(associativity_of_join, axiom, ![Z, X, Y]: join(X, join(Y, Z))=join(join(X, Y), Z)). 0.88/1.03 fof(associativity_of_meet, axiom, ![Z, X, Y]: meet(meet(X, Y), Z)=meet(X, meet(Y, Z))). 0.88/1.03 fof(commutativity_of_join, axiom, ![X, Y]: join(X, Y)=join(Y, X)). 0.88/1.03 fof(commutativity_of_meet, axiom, ![X, Y]: meet(Y, X)=meet(X, Y)). 0.88/1.03 fof(idempotence_of_meet, axiom, ![X]: meet(X, X)=X). 0.88/1.03 fof(nr_3, hypothesis, ![Z, X, Y]: join(meet(Z, join(X, meet(Y, Z))), meet(X, join(Y, Z)))=meet(join(X, meet(Y, Z)), join(Z, meet(X, Y)))). 0.88/1.03 fof(prove_this, negated_conjecture, meet(meet(a, meet(join(b, c), join(b, d))), join(meet(a, join(b, meet(c, d))), join(meet(a, c), meet(a, d))))!=meet(a, meet(join(b, c), join(b, d)))). 0.88/1.03 0.88/1.03 Now clausify the problem and encode Horn clauses using encoding 3 of 0.88/1.03 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.88/1.03 We repeatedly replace C & s=t => u=v by the two clauses: 0.88/1.03 fresh(y, y, x1...xn) = u 0.88/1.03 C => fresh(s, t, x1...xn) = v 0.88/1.03 where fresh is a fresh function symbol and x1..xn are the free 0.88/1.03 variables of u and v. 0.88/1.03 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.88/1.03 input problem has no model of domain size 1). 0.88/1.03 0.88/1.03 The encoding turns the above axioms into the following unit equations and goals: 0.88/1.03 0.88/1.03 Axiom 1 (commutativity_of_join): join(X, Y) = join(Y, X). 0.88/1.03 Axiom 2 (idempotence_of_meet): meet(X, X) = X. 0.88/1.03 Axiom 3 (commutativity_of_meet): meet(X, Y) = meet(Y, X). 0.88/1.03 Axiom 4 (absorption2): X = join(X, meet(X, Y)). 0.88/1.03 Axiom 5 (absorption1): meet(X, join(X, Y)) = X. 0.88/1.03 Axiom 6 (associativity_of_join): join(X, join(Y, Z)) = join(join(X, Y), Z). 0.88/1.03 Axiom 7 (associativity_of_meet): meet(meet(X, Y), Z) = meet(X, meet(Y, Z)). 0.88/1.03 Axiom 8 (nr_3): join(meet(X, join(Y, meet(Z, X))), meet(Y, join(Z, X))) = meet(join(Y, meet(Z, X)), join(X, meet(Y, Z))). 0.88/1.03 0.88/1.03 Lemma 9: join(X, meet(Y, X)) = X. 0.88/1.03 Proof: 0.88/1.03 join(X, meet(Y, X)) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(X, meet(X, Y)) 0.88/1.03 = { by axiom 4 (absorption2) } 0.88/1.03 X 0.88/1.03 0.88/1.03 Lemma 10: join(X, meet(Y, meet(Z, X))) = X. 0.88/1.03 Proof: 0.88/1.03 join(X, meet(Y, meet(Z, X))) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 join(X, meet(meet(Y, Z), X)) 0.88/1.03 = { by lemma 9 } 0.88/1.03 X 0.88/1.03 0.88/1.03 Lemma 11: join(meet(Y, join(Z, X)), meet(X, join(Y, meet(Z, X)))) = meet(join(Y, meet(Z, X)), join(X, meet(Y, Z))). 0.88/1.03 Proof: 0.88/1.03 join(meet(Y, join(Z, X)), meet(X, join(Y, meet(Z, X)))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(Y, join(Z, X))) 0.88/1.03 = { by axiom 8 (nr_3) } 0.88/1.03 meet(join(Y, meet(Z, X)), join(X, meet(Y, Z))) 0.88/1.03 0.88/1.03 Lemma 12: meet(X, meet(Y, join(Z, meet(X, Y)))) = meet(X, Y). 0.88/1.03 Proof: 0.88/1.03 meet(X, meet(Y, join(Z, meet(X, Y)))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 meet(X, meet(Y, join(meet(X, Y), Z))) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 meet(meet(X, Y), join(meet(X, Y), Z)) 0.88/1.03 = { by axiom 5 (absorption1) } 0.88/1.03 meet(X, Y) 0.88/1.03 0.88/1.03 Lemma 13: join(meet(X, Z), meet(X, join(Y, meet(X, Z)))) = meet(X, join(Y, meet(X, Z))). 0.88/1.03 Proof: 0.88/1.03 join(meet(X, Z), meet(X, join(Y, meet(X, Z)))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(Z, X), meet(X, join(Y, meet(X, Z)))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(Z, X), meet(X, join(Y, meet(Z, X)))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(Z, X)) 0.88/1.03 = { by lemma 12 } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(Z, meet(X, join(Y, meet(Z, X))))) 0.88/1.03 = { by lemma 9 } 0.88/1.03 meet(X, join(Y, meet(Z, X))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 meet(X, join(Y, meet(X, Z))) 0.88/1.03 0.88/1.03 Lemma 14: meet(X, join(meet(X, Y), meet(X, Z))) = meet(X, join(Y, meet(X, Z))). 0.88/1.03 Proof: 0.88/1.03 meet(X, join(meet(X, Y), meet(X, Z))) 0.88/1.03 = { by lemma 10 } 0.88/1.03 meet(join(X, meet(Y, meet(Z, X))), join(meet(X, Y), meet(X, Z))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 meet(join(X, meet(Y, meet(Z, X))), join(meet(X, Y), meet(Z, X))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 meet(join(X, meet(Y, meet(Z, X))), join(meet(Z, X), meet(X, Y))) 0.88/1.03 = { by lemma 11 } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(meet(Z, X), join(X, meet(Y, meet(Z, X))))) 0.88/1.03 = { by lemma 10 } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(meet(Z, X), X)) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(Z, meet(X, X))) 0.88/1.03 = { by axiom 2 (idempotence_of_meet) } 0.88/1.03 join(meet(X, join(Y, meet(Z, X))), meet(Z, X)) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 join(meet(Z, X), meet(X, join(Y, meet(Z, X)))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(X, Z), meet(X, join(Y, meet(Z, X)))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(X, Z), meet(X, join(Y, meet(X, Z)))) 0.88/1.03 = { by lemma 13 } 0.88/1.03 meet(X, join(Y, meet(X, Z))) 0.88/1.03 0.88/1.03 Lemma 15: join(meet(X, Y), meet(X, Z)) = meet(X, join(Y, meet(X, Z))). 0.88/1.03 Proof: 0.88/1.03 join(meet(X, Y), meet(X, Z)) 0.88/1.03 = { by lemma 9 } 0.88/1.03 join(join(meet(X, Y), meet(X, Z)), meet(X, join(meet(X, Y), meet(X, Z)))) 0.88/1.03 = { by lemma 14 } 0.88/1.03 join(join(meet(X, Y), meet(X, Z)), meet(X, join(Y, meet(X, Z)))) 0.88/1.03 = { by axiom 6 (associativity_of_join) } 0.88/1.03 join(meet(X, Y), join(meet(X, Z), meet(X, join(Y, meet(X, Z))))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(Y, X), join(meet(X, Z), meet(X, join(Y, meet(X, Z))))) 0.88/1.03 = { by lemma 13 } 0.88/1.03 join(meet(Y, X), meet(X, join(Y, meet(X, Z)))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 join(meet(X, join(Y, meet(X, Z))), meet(Y, X)) 0.88/1.03 = { by axiom 5 (absorption1) } 0.88/1.03 join(meet(X, join(Y, meet(X, Z))), meet(meet(Y, join(Y, meet(X, Z))), X)) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 join(meet(X, join(Y, meet(X, Z))), meet(Y, meet(join(Y, meet(X, Z)), X))) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 join(meet(X, join(Y, meet(X, Z))), meet(Y, meet(X, join(Y, meet(X, Z))))) 0.88/1.03 = { by lemma 9 } 0.88/1.03 meet(X, join(Y, meet(X, Z))) 0.88/1.03 0.88/1.03 Lemma 16: meet(X, meet(Y, Z)) = meet(Y, meet(X, Z)). 0.88/1.03 Proof: 0.88/1.03 meet(X, meet(Y, Z)) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 meet(meet(X, Y), Z) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.03 meet(meet(Y, X), Z) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 meet(Y, meet(X, Z)) 0.88/1.03 0.88/1.03 Lemma 17: meet(X, join(Y, meet(X, Z))) = meet(X, join(Z, meet(X, Y))). 0.88/1.03 Proof: 0.88/1.03 meet(X, join(Y, meet(X, Z))) 0.88/1.03 = { by lemma 14 } 0.88/1.03 meet(X, join(meet(X, Y), meet(X, Z))) 0.88/1.03 = { by axiom 1 (commutativity_of_join) } 0.88/1.03 meet(X, join(meet(X, Z), meet(X, Y))) 0.88/1.03 = { by lemma 14 } 0.88/1.03 meet(X, join(Z, meet(X, Y))) 0.88/1.03 0.88/1.03 Lemma 18: meet(X, meet(Y, Z)) = meet(Z, meet(X, Y)). 0.88/1.03 Proof: 0.88/1.03 meet(X, meet(Y, Z)) 0.88/1.03 = { by axiom 7 (associativity_of_meet) } 0.88/1.03 meet(meet(X, Y), Z) 0.88/1.03 = { by axiom 3 (commutativity_of_meet) } 0.88/1.05 meet(Z, meet(X, Y)) 0.88/1.05 0.88/1.05 Goal 1 (prove_this): meet(meet(a, meet(join(b, c), join(b, d))), join(meet(a, join(b, meet(c, d))), join(meet(a, c), meet(a, d)))) = meet(a, meet(join(b, c), join(b, d))). 0.88/1.05 Proof: 0.88/1.05 meet(meet(a, meet(join(b, c), join(b, d))), join(meet(a, join(b, meet(c, d))), join(meet(a, c), meet(a, d)))) 0.88/1.05 = { by axiom 7 (associativity_of_meet) } 0.88/1.05 meet(a, meet(meet(join(b, c), join(b, d)), join(meet(a, join(b, meet(c, d))), join(meet(a, c), meet(a, d))))) 0.88/1.05 = { by axiom 7 (associativity_of_meet) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(meet(a, join(b, meet(c, d))), join(meet(a, c), meet(a, d)))))) 0.88/1.05 = { by axiom 1 (commutativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(join(meet(a, c), meet(a, d)), meet(a, join(b, meet(c, d))))))) 0.88/1.05 = { by axiom 6 (associativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(meet(a, c), join(meet(a, d), meet(a, join(b, meet(c, d)))))))) 0.88/1.05 = { by lemma 15 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(meet(a, c), meet(a, join(d, meet(a, join(b, meet(c, d))))))))) 0.88/1.05 = { by lemma 15 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), meet(a, join(c, meet(a, join(d, meet(a, join(b, meet(c, d)))))))))) 0.88/1.05 = { by lemma 16 } 0.88/1.05 meet(a, meet(join(b, c), meet(a, meet(join(b, d), join(c, meet(a, join(d, meet(a, join(b, meet(c, d)))))))))) 0.88/1.05 = { by lemma 16 } 0.88/1.05 meet(a, meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, meet(a, join(b, meet(c, d)))))))))) 0.88/1.05 = { by axiom 7 (associativity_of_meet) } 0.88/1.05 meet(meet(a, a), meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, meet(a, join(b, meet(c, d))))))))) 0.88/1.05 = { by axiom 2 (idempotence_of_meet) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, meet(a, join(b, meet(c, d))))))))) 0.88/1.05 = { by lemma 17 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(join(b, meet(c, d)), meet(a, d))))))) 0.88/1.05 = { by axiom 3 (commutativity_of_meet) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(join(join(b, meet(c, d)), meet(a, d)), a))))) 0.88/1.05 = { by axiom 5 (absorption1) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(join(join(b, meet(c, d)), meet(a, d)), meet(a, join(a, meet(d, join(b, meet(c, d)))))))))) 0.88/1.05 = { by lemma 18 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(join(a, meet(d, join(b, meet(c, d)))), meet(join(join(b, meet(c, d)), meet(a, d)), a)))))) 0.88/1.05 = { by lemma 18 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, meet(join(a, meet(d, join(b, meet(c, d)))), join(join(b, meet(c, d)), meet(a, d)))))))) 0.88/1.05 = { by lemma 11 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(meet(a, join(d, join(b, meet(c, d)))), meet(join(b, meet(c, d)), join(a, meet(d, join(b, meet(c, d))))))))))) 0.88/1.05 = { by axiom 1 (commutativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(meet(join(b, meet(c, d)), join(a, meet(d, join(b, meet(c, d))))), meet(a, join(d, join(b, meet(c, d)))))))))) 0.88/1.05 = { by lemma 17 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(join(d, join(b, meet(c, d))), meet(a, meet(join(b, meet(c, d)), join(a, meet(d, join(b, meet(c, d)))))))))))) 0.88/1.05 = { by axiom 6 (associativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, join(join(b, meet(c, d)), meet(a, meet(join(b, meet(c, d)), join(a, meet(d, join(b, meet(c, d))))))))))))) 0.88/1.05 = { by lemma 18 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, join(join(b, meet(c, d)), meet(join(b, meet(c, d)), meet(join(a, meet(d, join(b, meet(c, d)))), a))))))))) 0.88/1.05 = { by axiom 4 (absorption2) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(d, join(b, meet(c, d)))))))) 0.88/1.05 = { by axiom 6 (associativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(join(d, b), meet(c, d))))))) 0.88/1.05 = { by axiom 1 (commutativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(join(b, d), meet(c, d))))))) 0.88/1.05 = { by axiom 6 (associativity_of_join) } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(b, join(d, meet(c, d)))))))) 0.88/1.05 = { by lemma 9 } 0.88/1.05 meet(a, meet(join(b, c), meet(join(b, d), join(c, meet(a, join(b, d)))))) 0.88/1.05 = { by lemma 16 } 0.88/1.05 meet(join(b, c), meet(a, meet(join(b, d), join(c, meet(a, join(b, d)))))) 0.88/1.05 = { by lemma 12 } 0.88/1.05 meet(join(b, c), meet(a, join(b, d))) 0.88/1.05 = { by lemma 16 } 0.88/1.05 meet(a, meet(join(b, c), join(b, d))) 0.88/1.05 % SZS output end Proof 0.88/1.05 0.88/1.05 RESULT: Unsatisfiable (the axioms are contradictory). 0.88/1.05 EOF