0.07/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.07/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.13/0.33 % Computer : n003.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 09:59:17 EDT 2019 0.13/0.33 % CPUTime : 0.19/0.41 % SZS status Unsatisfiable 0.19/0.41 0.19/0.41 % SZS output start Proof 0.19/0.41 Take the following subset of the input axioms: 0.19/0.41 fof(prove_normal_axioms_4, negated_conjecture, join(a, b)!=join(b, a)). 0.19/0.41 fof(wal_absorbtion_1, axiom, ![A, B]: A=join(meet(A, B), meet(A, join(A, B)))). 0.19/0.41 fof(wal_absorbtion_2, axiom, ![A, B]: A=join(meet(A, A), meet(B, join(A, A)))). 0.19/0.41 fof(wal_absorbtion_3, axiom, ![A, B]: join(meet(A, B), meet(B, join(A, B)))=B). 0.19/0.41 fof(wal_absorbtion_4, axiom, ![A, B, C]: A=meet(meet(join(A, B), join(C, A)), A)). 0.19/0.41 fof(wal_absorbtion_5, axiom, ![A, B, C]: join(join(meet(A, B), meet(C, A)), A)=A). 0.19/0.41 0.19/0.41 Now clausify the problem and encode Horn clauses using encoding 3 of 0.19/0.41 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.19/0.41 We repeatedly replace C & s=t => u=v by the two clauses: 0.19/0.41 fresh(y, y, x1...xn) = u 0.19/0.41 C => fresh(s, t, x1...xn) = v 0.19/0.41 where fresh is a fresh function symbol and x1..xn are the free 0.19/0.41 variables of u and v. 0.19/0.41 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.19/0.41 input problem has no model of domain size 1). 0.19/0.41 0.19/0.41 The encoding turns the above axioms into the following unit equations and goals: 0.19/0.41 0.19/0.41 Axiom 1 (wal_absorbtion_5): join(join(meet(X, Y), meet(Z, X)), X) = X. 0.19/0.41 Axiom 2 (wal_absorbtion_4): X = meet(meet(join(X, Y), join(Z, X)), X). 0.19/0.41 Axiom 3 (wal_absorbtion_3): join(meet(X, Y), meet(Y, join(X, Y))) = Y. 0.19/0.41 Axiom 4 (wal_absorbtion_1): X = join(meet(X, Y), meet(X, join(X, Y))). 0.19/0.41 Axiom 5 (wal_absorbtion_2): X = join(meet(X, X), meet(Y, join(X, X))). 0.19/0.41 0.19/0.41 Lemma 6: meet(meet(join(X, Y), X), X) = X. 0.19/0.41 Proof: 0.19/0.41 meet(meet(join(X, Y), X), X) 0.19/0.41 = { by axiom 1 (wal_absorbtion_5) } 0.19/0.41 meet(meet(join(X, Y), join(join(meet(X, ?), meet(?, X)), X)), X) 0.19/0.41 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 7: meet(X, X) = X. 0.19/0.42 Proof: 0.19/0.42 meet(X, X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(meet(meet(join(X, ?), join(?, X)), X), X) 0.19/0.42 = { by axiom 4 (wal_absorbtion_1) } 0.19/0.42 meet(meet(join(meet(meet(join(X, ?), join(?, X)), X), meet(meet(join(X, ?), join(?, X)), join(meet(join(X, ?), join(?, X)), X))), X), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(meet(join(meet(meet(join(X, ?), join(?, X)), X), meet(meet(join(X, ?), join(?, X)), join(meet(join(X, ?), join(?, X)), X))), meet(meet(join(X, ?), join(?, X)), X)), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(meet(join(meet(meet(join(X, ?), join(?, X)), X), meet(meet(join(X, ?), join(?, X)), join(meet(join(X, ?), join(?, X)), X))), meet(meet(join(X, ?), join(?, X)), X)), meet(meet(join(X, ?), join(?, X)), X)) 0.19/0.42 = { by lemma 6 } 0.19/0.42 meet(meet(join(X, ?), join(?, X)), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 8: meet(join(X, X), X) = X. 0.19/0.42 Proof: 0.19/0.42 meet(join(X, X), X) 0.19/0.42 = { by lemma 7 } 0.19/0.42 meet(meet(join(X, X), join(X, X)), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 9: join(join(meet(X, Y), X), X) = X. 0.19/0.42 Proof: 0.19/0.42 join(join(meet(X, Y), X), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 join(join(meet(X, Y), meet(meet(join(X, ?), join(?, X)), X)), X) 0.19/0.42 = { by axiom 1 (wal_absorbtion_5) } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 10: join(X, X) = X. 0.19/0.42 Proof: 0.19/0.42 join(X, X) 0.19/0.42 = { by lemma 8 } 0.19/0.42 join(meet(join(X, X), X), X) 0.19/0.42 = { by lemma 7 } 0.19/0.42 join(meet(join(X, X), X), meet(X, X)) 0.19/0.42 = { by lemma 9 } 0.19/0.42 join(meet(join(X, X), X), meet(X, join(join(meet(X, X), X), X))) 0.19/0.42 = { by lemma 7 } 0.19/0.42 join(meet(join(X, X), X), meet(X, join(join(X, X), X))) 0.19/0.42 = { by axiom 3 (wal_absorbtion_3) } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 11: meet(meet(Y, join(Z, meet(X, Y))), meet(X, Y)) = meet(X, Y). 0.19/0.42 Proof: 0.19/0.42 meet(meet(Y, join(Z, meet(X, Y))), meet(X, Y)) 0.19/0.42 = { by axiom 3 (wal_absorbtion_3) } 0.19/0.42 meet(meet(join(meet(X, Y), meet(Y, join(X, Y))), join(Z, meet(X, Y))), meet(X, Y)) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(X, Y) 0.19/0.42 0.19/0.42 Lemma 12: meet(Y, meet(X, Y)) = meet(X, Y). 0.19/0.42 Proof: 0.19/0.42 meet(Y, meet(X, Y)) 0.19/0.42 = { by lemma 8 } 0.19/0.42 meet(meet(join(Y, Y), Y), meet(X, Y)) 0.19/0.42 = { by axiom 5 (wal_absorbtion_2) } 0.19/0.42 meet(meet(join(Y, Y), join(meet(Y, Y), meet(X, join(Y, Y)))), meet(X, Y)) 0.19/0.42 = { by lemma 10 } 0.19/0.42 meet(meet(join(Y, Y), join(meet(Y, Y), meet(X, join(Y, Y)))), meet(X, join(Y, Y))) 0.19/0.42 = { by lemma 11 } 0.19/0.42 meet(X, join(Y, Y)) 0.19/0.42 = { by lemma 10 } 0.19/0.42 meet(X, Y) 0.19/0.42 0.19/0.42 Lemma 13: meet(meet(X, Y), Y) = meet(X, Y). 0.19/0.42 Proof: 0.19/0.42 meet(meet(X, Y), Y) 0.19/0.42 = { by lemma 10 } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), Y)) 0.19/0.42 = { by axiom 4 (wal_absorbtion_1) } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(Y, meet(X, Y)), meet(Y, join(Y, meet(X, Y)))))) 0.19/0.42 = { by lemma 12 } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(X, Y), meet(Y, join(Y, meet(X, Y)))))) 0.19/0.42 = { by lemma 7 } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(X, Y), meet(Y, join(meet(Y, Y), meet(X, Y)))))) 0.19/0.42 = { by lemma 10 } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(X, Y), meet(Y, join(meet(Y, Y), meet(X, join(Y, Y))))))) 0.19/0.42 = { by axiom 5 (wal_absorbtion_2) } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(X, Y), meet(Y, Y)))) 0.19/0.42 = { by lemma 7 } 0.19/0.42 join(meet(meet(X, Y), Y), meet(meet(X, Y), join(meet(X, Y), Y))) 0.19/0.42 = { by axiom 4 (wal_absorbtion_1) } 0.19/0.42 meet(X, Y) 0.19/0.42 0.19/0.42 Lemma 14: meet(join(X, Y), X) = X. 0.19/0.42 Proof: 0.19/0.42 meet(join(X, Y), X) 0.19/0.42 = { by lemma 13 } 0.19/0.42 meet(meet(join(X, Y), X), X) 0.19/0.42 = { by lemma 6 } 0.19/0.42 X 0.19/0.42 0.19/0.42 Lemma 15: meet(join(meet(X, Y), X), X) = join(meet(X, Y), X). 0.19/0.42 Proof: 0.19/0.42 meet(join(meet(X, Y), X), X) 0.19/0.42 = { by lemma 10 } 0.19/0.42 join(meet(join(meet(X, Y), X), X), meet(join(meet(X, Y), X), X)) 0.19/0.42 = { by lemma 9 } 0.19/0.42 join(meet(join(meet(X, Y), X), X), meet(join(meet(X, Y), X), join(join(meet(X, Y), X), X))) 0.19/0.42 = { by axiom 4 (wal_absorbtion_1) } 0.19/0.42 join(meet(X, Y), X) 0.19/0.42 0.19/0.42 Lemma 16: meet(meet(X, join(W, X)), X) = X. 0.19/0.42 Proof: 0.19/0.42 meet(meet(X, join(W, X)), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(meet(X, join(W, meet(meet(join(X, ?), join(?, X)), X))), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.42 meet(meet(X, join(W, meet(meet(join(X, ?), join(?, X)), X))), meet(meet(join(X, ?), join(?, X)), X)) 0.19/0.42 = { by lemma 11 } 0.19/0.42 meet(meet(join(X, ?), join(?, X)), X) 0.19/0.42 = { by axiom 2 (wal_absorbtion_4) } 0.19/0.43 X 0.19/0.43 0.19/0.43 Lemma 17: meet(meet(X, Y), X) = meet(X, Y). 0.19/0.43 Proof: 0.19/0.43 meet(meet(X, Y), X) 0.19/0.43 = { by lemma 10 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), X)) 0.19/0.43 = { by lemma 16 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(X, join(meet(X, Y), X)), X))) 0.19/0.43 = { by lemma 13 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(meet(X, join(meet(X, Y), X)), join(meet(X, Y), X)), X))) 0.19/0.43 = { by axiom 3 (wal_absorbtion_3) } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(meet(join(meet(join(meet(X, Y), X), X), meet(X, join(join(meet(X, Y), X), X))), join(meet(X, Y), X)), join(meet(X, Y), X)), X))) 0.19/0.43 = { by lemma 15 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(meet(join(meet(join(meet(X, Y), X), X), meet(X, join(join(meet(X, Y), X), X))), meet(join(meet(X, Y), X), X)), join(meet(X, Y), X)), X))) 0.19/0.43 = { by lemma 15 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(meet(join(meet(join(meet(X, Y), X), X), meet(X, join(join(meet(X, Y), X), X))), meet(join(meet(X, Y), X), X)), meet(join(meet(X, Y), X), X)), X))) 0.19/0.43 = { by lemma 6 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(meet(join(meet(X, Y), X), X), X))) 0.19/0.43 = { by lemma 15 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), meet(join(meet(X, Y), X), X))) 0.19/0.43 = { by lemma 15 } 0.19/0.43 join(meet(meet(X, Y), X), meet(meet(X, Y), join(meet(X, Y), X))) 0.19/0.43 = { by axiom 4 (wal_absorbtion_1) } 0.19/0.43 meet(X, Y) 0.19/0.43 0.19/0.43 Lemma 18: join(join(Y, X), join(X, Y)) = join(X, Y). 0.19/0.43 Proof: 0.19/0.43 join(join(Y, X), join(X, Y)) 0.19/0.43 = { by lemma 16 } 0.19/0.43 join(join(meet(meet(Y, join(X, Y)), Y), X), join(X, Y)) 0.19/0.43 = { by lemma 17 } 0.19/0.43 join(join(meet(Y, join(X, Y)), X), join(X, Y)) 0.19/0.43 = { by lemma 12 } 0.19/0.43 join(join(meet(join(X, Y), meet(Y, join(X, Y))), X), join(X, Y)) 0.19/0.43 = { by lemma 14 } 0.19/0.43 join(join(meet(join(X, Y), meet(Y, join(X, Y))), meet(join(X, Y), X)), join(X, Y)) 0.19/0.43 = { by lemma 17 } 0.19/0.43 join(join(meet(join(X, Y), meet(Y, join(X, Y))), meet(meet(join(X, Y), X), join(X, Y))), join(X, Y)) 0.19/0.43 = { by lemma 14 } 0.19/0.43 join(join(meet(join(X, Y), meet(Y, join(X, Y))), meet(X, join(X, Y))), join(X, Y)) 0.19/0.43 = { by axiom 1 (wal_absorbtion_5) } 0.19/0.43 join(X, Y) 0.19/0.43 0.19/0.43 Goal 1 (prove_normal_axioms_4): join(a, b) = join(b, a). 0.19/0.43 Proof: 0.19/0.43 join(a, b) 0.19/0.43 = { by lemma 18 } 0.19/0.43 join(join(b, a), join(a, b)) 0.19/0.43 = { by lemma 18 } 0.19/0.43 join(join(join(a, b), join(b, a)), join(a, b)) 0.19/0.43 = { by lemma 7 } 0.19/0.43 join(meet(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), join(a, b)) 0.19/0.43 = { by lemma 14 } 0.19/0.43 join(meet(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), meet(join(join(a, b), join(b, a)), join(a, b))) 0.19/0.43 = { by lemma 10 } 0.19/0.43 join(meet(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), meet(join(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), join(a, b))) 0.19/0.43 = { by lemma 17 } 0.19/0.43 join(meet(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), meet(meet(join(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))), join(a, b)), join(join(join(a, b), join(b, a)), join(join(a, b), join(b, a))))) 0.19/0.43 = { by axiom 5 (wal_absorbtion_2) } 0.19/0.43 join(join(a, b), join(b, a)) 0.19/0.43 = { by lemma 18 } 0.19/0.43 join(b, a) 0.19/0.43 % SZS output end Proof 0.19/0.43 0.19/0.43 RESULT: Unsatisfiable (the axioms are contradictory). 0.19/0.43 EOF