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 0.12/0.33 % Computer : n017.cluster.edu 0.12/0.33 % Model : x86_64 x86_64 0.12/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.12/0.33 % Memory : 8042.1875MB 0.12/0.33 % OS : Linux 3.10.0-693.el7.x86_64 0.12/0.33 % CPULimit : 180 0.12/0.33 % DateTime : Thu Aug 29 13:04:19 EDT 2019 0.12/0.33 % CPUTime : 1.70/1.90 % SZS status Unsatisfiable 1.70/1.90 1.70/1.90 % SZS output start Proof 1.70/1.90 Take the following subset of the input axioms: 1.70/1.91 fof(composition_associativity_5, axiom, ![A, B, C]: composition(composition(A, B), C)=composition(A, composition(B, C))). 1.70/1.91 fof(composition_identity_6, axiom, ![A]: A=composition(A, one)). 1.70/1.91 fof(converse_additivity_9, axiom, ![A, B]: join(converse(A), converse(B))=converse(join(A, B))). 1.70/1.91 fof(converse_cancellativity_11, axiom, ![A, B]: join(composition(converse(A), complement(composition(A, B))), complement(B))=complement(B)). 1.70/1.91 fof(converse_idempotence_8, axiom, ![A]: converse(converse(A))=A). 1.70/1.91 fof(converse_multiplicativity_10, axiom, ![A, B]: converse(composition(A, B))=composition(converse(B), converse(A))). 1.70/1.91 fof(def_top_12, axiom, ![A]: join(A, complement(A))=top). 1.70/1.91 fof(def_zero_13, axiom, ![A]: zero=meet(A, complement(A))). 1.70/1.91 fof(goals_14, negated_conjecture, complement(sk1)!=join(composition(complement(composition(sk1, sk2)), converse(sk2)), complement(sk1))). 1.70/1.91 fof(maddux1_join_commutativity_1, axiom, ![A, B]: join(B, A)=join(A, B)). 1.70/1.91 fof(maddux2_join_associativity_2, axiom, ![A, B, C]: join(join(A, B), C)=join(A, join(B, C))). 1.70/1.91 fof(maddux3_a_kind_of_de_Morgan_3, axiom, ![A, B]: join(complement(join(complement(A), complement(B))), complement(join(complement(A), B)))=A). 1.70/1.91 fof(maddux4_definiton_of_meet_4, axiom, ![A, B]: complement(join(complement(A), complement(B)))=meet(A, B)). 1.70/1.91 1.70/1.91 Now clausify the problem and encode Horn clauses using encoding 3 of 1.70/1.91 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 1.70/1.91 We repeatedly replace C & s=t => u=v by the two clauses: 1.70/1.91 fresh(y, y, x1...xn) = u 1.70/1.91 C => fresh(s, t, x1...xn) = v 1.70/1.91 where fresh is a fresh function symbol and x1..xn are the free 1.70/1.91 variables of u and v. 1.70/1.91 A predicate p(X) is encoded as p(X)=true (this is sound, because the 1.70/1.91 input problem has no model of domain size 1). 1.70/1.91 1.70/1.91 The encoding turns the above axioms into the following unit equations and goals: 1.70/1.91 1.70/1.91 Axiom 1 (maddux1_join_commutativity_1): join(X, Y) = join(Y, X). 1.70/1.91 Axiom 2 (maddux4_definiton_of_meet_4): complement(join(complement(X), complement(Y))) = meet(X, Y). 1.70/1.91 Axiom 3 (composition_identity_6): X = composition(X, one). 1.70/1.91 Axiom 4 (maddux3_a_kind_of_de_Morgan_3): join(complement(join(complement(X), complement(Y))), complement(join(complement(X), Y))) = X. 1.70/1.91 Axiom 5 (converse_idempotence_8): converse(converse(X)) = X. 1.70/1.91 Axiom 6 (maddux2_join_associativity_2): join(join(X, Y), Z) = join(X, join(Y, Z)). 1.70/1.91 Axiom 7 (converse_cancellativity_11): join(composition(converse(X), complement(composition(X, Y))), complement(Y)) = complement(Y). 1.70/1.91 Axiom 8 (def_zero_13): zero = meet(X, complement(X)). 1.70/1.91 Axiom 9 (def_top_12): join(X, complement(X)) = top. 1.70/1.91 Axiom 10 (converse_multiplicativity_10): converse(composition(X, Y)) = composition(converse(Y), converse(X)). 1.70/1.91 Axiom 11 (converse_additivity_9): join(converse(X), converse(Y)) = converse(join(X, Y)). 1.78/1.95 Axiom 12 (composition_associativity_5): composition(composition(X, Y), Z) = composition(X, composition(Y, Z)). 1.78/1.95 1.78/1.95 Lemma 13: complement(top) = zero. 1.78/1.95 Proof: 1.78/1.95 complement(top) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 complement(join(complement(?), complement(complement(?)))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 meet(?, complement(?)) 1.78/1.95 = { by axiom 8 (def_zero_13) } 1.78/1.95 zero 1.78/1.95 1.78/1.95 Lemma 14: meet(X, Y) = meet(Y, X). 1.78/1.95 Proof: 1.78/1.95 meet(X, Y) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 complement(join(complement(X), complement(Y))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(complement(Y), complement(X))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 meet(Y, X) 1.78/1.95 1.78/1.95 Lemma 15: complement(join(zero, complement(X))) = meet(X, top). 1.78/1.95 Proof: 1.78/1.95 complement(join(zero, complement(X))) 1.78/1.95 = { by lemma 13 } 1.78/1.95 complement(join(complement(top), complement(X))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 meet(top, X) 1.78/1.95 = { by lemma 14 } 1.78/1.95 meet(X, top) 1.78/1.95 1.78/1.95 Lemma 16: converse(composition(converse(X), Y)) = composition(converse(Y), X). 1.78/1.95 Proof: 1.78/1.95 converse(composition(converse(X), Y)) 1.78/1.95 = { by axiom 10 (converse_multiplicativity_10) } 1.78/1.95 composition(converse(Y), converse(converse(X))) 1.78/1.95 = { by axiom 5 (converse_idempotence_8) } 1.78/1.95 composition(converse(Y), X) 1.78/1.95 1.78/1.95 Lemma 17: composition(converse(one), X) = X. 1.78/1.95 Proof: 1.78/1.95 composition(converse(one), X) 1.78/1.95 = { by lemma 16 } 1.78/1.95 converse(composition(converse(X), one)) 1.78/1.95 = { by axiom 3 (composition_identity_6) } 1.78/1.95 converse(converse(X)) 1.78/1.95 = { by axiom 5 (converse_idempotence_8) } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 18: join(complement(Y), composition(converse(X), complement(composition(X, Y)))) = complement(Y). 1.78/1.95 Proof: 1.78/1.95 join(complement(Y), composition(converse(X), complement(composition(X, Y)))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(composition(converse(X), complement(composition(X, Y))), complement(Y)) 1.78/1.95 = { by axiom 7 (converse_cancellativity_11) } 1.78/1.95 complement(Y) 1.78/1.95 1.78/1.95 Lemma 19: join(complement(X), complement(X)) = complement(X). 1.78/1.95 Proof: 1.78/1.95 join(complement(X), complement(X)) 1.78/1.95 = { by lemma 17 } 1.78/1.95 join(complement(X), composition(converse(one), complement(X))) 1.78/1.95 = { by lemma 17 } 1.78/1.95 join(complement(X), composition(converse(one), complement(composition(converse(one), X)))) 1.78/1.95 = { by axiom 3 (composition_identity_6) } 1.78/1.95 join(complement(X), composition(converse(one), complement(composition(composition(converse(one), one), X)))) 1.78/1.95 = { by axiom 12 (composition_associativity_5) } 1.78/1.95 join(complement(X), composition(converse(one), complement(composition(converse(one), composition(one, X))))) 1.78/1.95 = { by lemma 17 } 1.78/1.95 join(complement(X), composition(converse(one), complement(composition(one, X)))) 1.78/1.95 = { by lemma 18 } 1.78/1.95 complement(X) 1.78/1.95 1.78/1.95 Lemma 20: meet(X, X) = complement(complement(X)). 1.78/1.95 Proof: 1.78/1.95 meet(X, X) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 complement(join(complement(X), complement(X))) 1.78/1.95 = { by lemma 19 } 1.78/1.95 complement(complement(X)) 1.78/1.95 1.78/1.95 Lemma 21: join(meet(X, Y), complement(join(complement(X), Y))) = X. 1.78/1.95 Proof: 1.78/1.95 join(meet(X, Y), complement(join(complement(X), Y))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 join(complement(join(complement(X), complement(Y))), complement(join(complement(X), Y))) 1.78/1.95 = { by axiom 4 (maddux3_a_kind_of_de_Morgan_3) } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 22: join(meet(X, Y), meet(X, complement(Y))) = X. 1.78/1.95 Proof: 1.78/1.95 join(meet(X, Y), meet(X, complement(Y))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(meet(X, complement(Y)), meet(X, Y)) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 join(meet(X, complement(Y)), complement(join(complement(X), complement(Y)))) 1.78/1.95 = { by lemma 21 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 23: join(zero, complement(complement(X))) = X. 1.78/1.95 Proof: 1.78/1.95 join(zero, complement(complement(X))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(complement(complement(X)), zero) 1.78/1.95 = { by lemma 20 } 1.78/1.95 join(meet(X, X), zero) 1.78/1.95 = { by axiom 8 (def_zero_13) } 1.78/1.95 join(meet(X, X), meet(X, complement(X))) 1.78/1.95 = { by lemma 22 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 24: join(X, join(Y, Z)) = join(Z, join(X, Y)). 1.78/1.95 Proof: 1.78/1.95 join(X, join(Y, Z)) 1.78/1.95 = { by axiom 6 (maddux2_join_associativity_2) } 1.78/1.95 join(join(X, Y), Z) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(Z, join(X, Y)) 1.78/1.95 1.78/1.95 Lemma 25: join(X, join(complement(X), Y)) = join(Y, top). 1.78/1.95 Proof: 1.78/1.95 join(X, join(complement(X), Y)) 1.78/1.95 = { by lemma 24 } 1.78/1.95 join(complement(X), join(Y, X)) 1.78/1.95 = { by lemma 24 } 1.78/1.95 join(Y, join(X, complement(X))) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 join(Y, top) 1.78/1.95 1.78/1.95 Lemma 26: join(X, top) = top. 1.78/1.95 Proof: 1.78/1.95 join(X, top) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 join(X, join(complement(X), complement(complement(X)))) 1.78/1.95 = { by lemma 25 } 1.78/1.95 join(complement(complement(X)), top) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(top, complement(complement(X))) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 join(join(complement(X), complement(complement(X))), complement(complement(X))) 1.78/1.95 = { by axiom 6 (maddux2_join_associativity_2) } 1.78/1.95 join(complement(X), join(complement(complement(X)), complement(complement(X)))) 1.78/1.95 = { by lemma 19 } 1.78/1.95 join(complement(X), complement(complement(X))) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 top 1.78/1.95 1.78/1.95 Lemma 27: join(zero, meet(X, top)) = X. 1.78/1.95 Proof: 1.78/1.95 join(zero, meet(X, top)) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(meet(X, top), zero) 1.78/1.95 = { by lemma 13 } 1.78/1.95 join(meet(X, top), complement(top)) 1.78/1.95 = { by lemma 26 } 1.78/1.95 join(meet(X, top), complement(join(complement(X), top))) 1.78/1.95 = { by lemma 21 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 28: join(zero, complement(X)) = complement(X). 1.78/1.95 Proof: 1.78/1.95 join(zero, complement(X)) 1.78/1.95 = { by lemma 23 } 1.78/1.95 join(zero, complement(join(zero, complement(complement(X))))) 1.78/1.95 = { by lemma 15 } 1.78/1.95 join(zero, meet(complement(X), top)) 1.78/1.95 = { by lemma 27 } 1.78/1.95 complement(X) 1.78/1.95 1.78/1.95 Lemma 29: meet(X, top) = X. 1.78/1.95 Proof: 1.78/1.95 meet(X, top) 1.78/1.95 = { by lemma 15 } 1.78/1.95 complement(join(zero, complement(X))) 1.78/1.95 = { by lemma 28 } 1.78/1.95 join(zero, complement(join(zero, complement(X)))) 1.78/1.95 = { by lemma 15 } 1.78/1.95 join(zero, meet(X, top)) 1.78/1.95 = { by lemma 27 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 30: complement(complement(X)) = X. 1.78/1.95 Proof: 1.78/1.95 complement(complement(X)) 1.78/1.95 = { by lemma 28 } 1.78/1.95 join(zero, complement(complement(X))) 1.78/1.95 = { by lemma 23 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 31: join(X, zero) = X. 1.78/1.95 Proof: 1.78/1.95 join(X, zero) 1.78/1.95 = { by lemma 30 } 1.78/1.95 join(complement(complement(X)), zero) 1.78/1.95 = { by lemma 20 } 1.78/1.95 join(meet(X, X), zero) 1.78/1.95 = { by axiom 8 (def_zero_13) } 1.78/1.95 join(meet(X, X), meet(X, complement(X))) 1.78/1.95 = { by lemma 22 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 32: join(zero, X) = X. 1.78/1.95 Proof: 1.78/1.95 join(zero, X) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 join(X, zero) 1.78/1.95 = { by lemma 31 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 33: meet(top, X) = X. 1.78/1.95 Proof: 1.78/1.95 meet(top, X) 1.78/1.95 = { by lemma 14 } 1.78/1.95 meet(X, top) 1.78/1.95 = { by lemma 29 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 34: complement(join(X, complement(Y))) = meet(Y, complement(X)). 1.78/1.95 Proof: 1.78/1.95 complement(join(X, complement(Y))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(complement(Y), X)) 1.78/1.95 = { by lemma 33 } 1.78/1.95 complement(join(complement(Y), meet(top, X))) 1.78/1.95 = { by lemma 14 } 1.78/1.95 complement(join(complement(Y), meet(X, top))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(meet(X, top), complement(Y))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 complement(join(complement(join(complement(X), complement(top))), complement(Y))) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 meet(join(complement(X), complement(top)), Y) 1.78/1.95 = { by lemma 14 } 1.78/1.95 meet(Y, join(complement(X), complement(top))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 meet(Y, join(complement(top), complement(X))) 1.78/1.95 = { by lemma 13 } 1.78/1.95 meet(Y, join(zero, complement(X))) 1.78/1.95 = { by lemma 28 } 1.78/1.95 meet(Y, complement(X)) 1.78/1.95 1.78/1.95 Lemma 35: complement(join(complement(X), Y)) = meet(X, complement(Y)). 1.78/1.95 Proof: 1.78/1.95 complement(join(complement(X), Y)) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(Y, complement(X))) 1.78/1.95 = { by lemma 34 } 1.78/1.95 meet(X, complement(Y)) 1.78/1.95 1.78/1.95 Lemma 36: meet(join(X, Y), join(X, complement(Y))) = X. 1.78/1.95 Proof: 1.78/1.95 meet(join(X, Y), join(X, complement(Y))) 1.78/1.95 = { by lemma 29 } 1.78/1.95 meet(join(X, Y), meet(join(X, complement(Y)), top)) 1.78/1.95 = { by lemma 15 } 1.78/1.95 meet(join(X, Y), complement(join(zero, complement(join(X, complement(Y)))))) 1.78/1.95 = { by lemma 34 } 1.78/1.95 meet(join(X, Y), complement(join(zero, meet(Y, complement(X))))) 1.78/1.95 = { by lemma 32 } 1.78/1.95 meet(join(X, Y), complement(meet(Y, complement(X)))) 1.78/1.95 = { by lemma 35 } 1.78/1.95 complement(join(complement(join(X, Y)), meet(Y, complement(X)))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(complement(join(Y, X)), meet(Y, complement(X)))) 1.78/1.95 = { by lemma 14 } 1.78/1.95 complement(join(complement(join(Y, X)), meet(complement(X), Y))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(meet(complement(X), Y), complement(join(Y, X)))) 1.78/1.95 = { by lemma 28 } 1.78/1.95 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, X)))) 1.78/1.95 = { by lemma 29 } 1.78/1.95 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, meet(X, top))))) 1.78/1.95 = { by lemma 15 } 1.78/1.95 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, complement(join(zero, complement(X))))))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(meet(join(zero, complement(X)), Y), complement(join(complement(join(zero, complement(X))), Y)))) 1.78/1.95 = { by lemma 21 } 1.78/1.95 complement(join(zero, complement(X))) 1.78/1.95 = { by lemma 28 } 1.78/1.95 complement(complement(X)) 1.78/1.95 = { by lemma 30 } 1.78/1.95 X 1.78/1.95 1.78/1.95 Lemma 37: converse(join(converse(X), Y)) = join(X, converse(Y)). 1.78/1.95 Proof: 1.78/1.95 converse(join(converse(X), Y)) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 converse(join(Y, converse(X))) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 converse(join(converse(X), Y)) 1.78/1.95 = { by axiom 11 (converse_additivity_9) } 1.78/1.95 join(converse(converse(X)), converse(Y)) 1.78/1.95 = { by axiom 5 (converse_idempotence_8) } 1.78/1.95 join(X, converse(Y)) 1.78/1.95 1.78/1.95 Lemma 38: join(X, converse(top)) = converse(top). 1.78/1.95 Proof: 1.78/1.95 join(X, converse(top)) 1.78/1.95 = { by lemma 37 } 1.78/1.95 converse(join(converse(X), top)) 1.78/1.95 = { by lemma 26 } 1.78/1.95 converse(top) 1.78/1.95 1.78/1.95 Lemma 39: join(X, converse(complement(converse(X)))) = top. 1.78/1.95 Proof: 1.78/1.95 join(X, converse(complement(converse(X)))) 1.78/1.95 = { by lemma 37 } 1.78/1.95 converse(join(converse(X), complement(converse(X)))) 1.78/1.95 = { by axiom 9 (def_top_12) } 1.78/1.95 converse(top) 1.78/1.95 = { by lemma 38 } 1.78/1.95 join(?, converse(top)) 1.78/1.95 = { by lemma 38 } 1.78/1.95 join(?, join(complement(?), converse(top))) 1.78/1.95 = { by lemma 25 } 1.78/1.95 join(converse(top), top) 1.78/1.95 = { by lemma 26 } 1.78/1.95 top 1.78/1.95 1.78/1.95 Lemma 40: meet(complement(X), complement(Y)) = complement(join(X, Y)). 1.78/1.95 Proof: 1.78/1.95 meet(complement(X), complement(Y)) 1.78/1.95 = { by lemma 28 } 1.78/1.95 meet(join(zero, complement(X)), complement(Y)) 1.78/1.95 = { by lemma 34 } 1.78/1.95 complement(join(Y, complement(join(zero, complement(X))))) 1.78/1.95 = { by lemma 15 } 1.78/1.95 complement(join(Y, meet(X, top))) 1.78/1.95 = { by lemma 29 } 1.78/1.95 complement(join(Y, X)) 1.78/1.95 = { by axiom 1 (maddux1_join_commutativity_1) } 1.78/1.95 complement(join(X, Y)) 1.78/1.95 1.78/1.95 Lemma 41: meet(X, meet(Y, complement(Z))) = meet(complement(Z), meet(X, Y)). 1.78/1.95 Proof: 1.78/1.95 meet(X, meet(Y, complement(Z))) 1.78/1.95 = { by lemma 35 } 1.78/1.95 meet(X, complement(join(complement(Y), Z))) 1.78/1.95 = { by lemma 35 } 1.78/1.95 complement(join(complement(X), join(complement(Y), Z))) 1.78/1.95 = { by axiom 6 (maddux2_join_associativity_2) } 1.78/1.95 complement(join(join(complement(X), complement(Y)), Z)) 1.78/1.95 = { by lemma 40 } 1.78/1.95 meet(complement(join(complement(X), complement(Y))), complement(Z)) 1.78/1.95 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.78/1.95 meet(meet(X, Y), complement(Z)) 1.78/1.95 = { by lemma 14 } 1.78/1.95 meet(complement(Z), meet(X, Y)) 1.78/1.95 1.78/1.95 Lemma 42: meet(meet(X, Z), Y) = meet(X, meet(Y, Z)). 1.78/1.95 Proof: 1.78/1.95 meet(meet(X, Z), Y) 1.78/1.95 = { by lemma 14 } 1.78/1.95 meet(Y, meet(X, Z)) 1.78/1.95 = { by lemma 29 } 1.78/1.95 meet(meet(Y, top), meet(X, Z)) 1.78/1.95 = { by lemma 15 } 1.78/1.95 meet(complement(join(zero, complement(Y))), meet(X, Z)) 1.78/1.95 = { by lemma 41 } 1.78/1.95 meet(X, meet(Z, complement(join(zero, complement(Y))))) 1.78/1.95 = { by lemma 15 } 1.78/1.95 meet(X, meet(Z, meet(Y, top))) 1.78/1.95 = { by lemma 29 } 1.78/1.95 meet(X, meet(Z, Y)) 1.78/1.95 = { by lemma 14 } 1.82/2.00 meet(X, meet(Y, Z)) 1.82/2.00 1.82/2.00 Lemma 43: converse(complement(converse(X))) = complement(X). 1.82/2.00 Proof: 1.82/2.00 converse(complement(converse(X))) 1.82/2.00 = { by lemma 29 } 1.82/2.00 converse(complement(converse(meet(X, top)))) 1.82/2.00 = { by lemma 15 } 1.82/2.00 converse(complement(converse(complement(join(zero, complement(X)))))) 1.82/2.00 = { by lemma 36 } 1.82/2.00 meet(join(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(X))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 meet(join(join(zero, complement(X)), converse(complement(converse(complement(join(zero, complement(X))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 meet(join(join(zero, complement(X)), converse(complement(converse(complement(converse(converse(join(zero, complement(X))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by lemma 37 } 1.82/2.00 meet(converse(join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by lemma 33 } 1.82/2.00 meet(converse(meet(top, join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X)))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by lemma 39 } 1.82/2.00 meet(converse(meet(join(converse(join(zero, complement(X))), converse(complement(converse(converse(join(zero, complement(X))))))), join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X)))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by lemma 36 } 1.82/2.00 meet(converse(converse(join(zero, complement(X)))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 meet(join(zero, complement(X)), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 meet(join(zero, complement(X)), join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 32 } 1.82/2.00 meet(join(zero, complement(X)), join(zero, join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X))))))))) 1.82/2.00 = { by axiom 6 (maddux2_join_associativity_2) } 1.82/2.00 meet(join(zero, complement(X)), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 29 } 1.82/2.00 meet(join(zero, complement(X)), meet(join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X))))))), top)) 1.82/2.00 = { by lemma 42 } 1.82/2.00 meet(meet(join(zero, complement(X)), top), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 15 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 30 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 22 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), complement(converse(complement(converse(complement(join(zero, complement(X))))))))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), meet(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))), complement(join(zero, complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 35 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), complement(join(complement(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), join(zero, complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 35 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), complement(join(complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))), join(complement(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), join(zero, complement(join(zero, complement(X)))))))) 1.82/2.00 = { by axiom 6 (maddux2_join_associativity_2) } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), complement(join(join(complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))))), join(zero, complement(join(zero, complement(X))))))) 1.82/2.00 = { by lemma 40 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(join(complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))))), complement(join(zero, complement(join(zero, complement(X))))))) 1.82/2.00 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), complement(join(zero, complement(join(zero, complement(X))))))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(join(zero, complement(join(zero, complement(X))))), meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(complement(join(zero, complement(join(zero, complement(X))))), meet(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 41 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))), meet(complement(converse(complement(converse(complement(join(zero, complement(X))))))), complement(join(zero, complement(join(zero, complement(X)))))))) 1.82/2.00 = { by lemma 34 } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), meet(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))), complement(join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))))) 1.82/2.00 = { by axiom 8 (def_zero_13) } 1.82/2.00 join(meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))), zero) 1.82/2.00 = { by lemma 31 } 1.82/2.00 meet(meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X)))))))))), converse(complement(converse(complement(join(zero, complement(X))))))) 1.82/2.00 = { by lemma 42 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(complement(converse(complement(join(zero, complement(X)))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), join(join(zero, complement(join(zero, complement(X)))), complement(complement(converse(complement(converse(complement(join(zero, complement(X))))))))))) 1.82/2.00 = { by lemma 30 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X))))))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(join(zero, complement(X))))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(converse(join(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(join(zero, complement(X))))))))) 1.82/2.00 = { by axiom 11 (converse_additivity_9) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X))))))))) 1.82/2.00 = { by lemma 31 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), zero)) 1.82/2.00 = { by lemma 13 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(top))) 1.82/2.00 = { by lemma 26 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(converse(converse(join(zero, complement(join(zero, complement(X)))))), top)))) 1.82/2.00 = { by axiom 9 (def_top_12) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(converse(converse(join(zero, complement(join(zero, complement(X)))))), join(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), complement(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))))))))) 1.82/2.00 = { by axiom 6 (maddux2_join_associativity_2) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(join(converse(converse(join(zero, complement(join(zero, complement(X)))))), converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))), complement(converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))))))) 1.82/2.00 = { by axiom 11 (converse_additivity_9) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(converse(join(converse(join(zero, complement(join(zero, complement(X))))), converse(converse(complement(converse(complement(join(zero, complement(X))))))))), complement(converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(complement(converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))), converse(join(converse(join(zero, complement(join(zero, complement(X))))), converse(converse(complement(converse(complement(join(zero, complement(X))))))))))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), join(meet(converse(converse(converse(complement(converse(complement(join(zero, complement(X)))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X)))))))), complement(join(complement(converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))), converse(join(converse(converse(complement(converse(complement(join(zero, complement(X))))))), converse(join(zero, complement(join(zero, complement(X))))))))))) 1.82/2.00 = { by lemma 21 } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), converse(converse(converse(complement(converse(complement(join(zero, complement(X))))))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 meet(complement(join(zero, complement(join(zero, complement(X))))), converse(complement(converse(complement(join(zero, complement(X))))))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 meet(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(join(zero, complement(X)))))) 1.82/2.00 = { by lemma 15 } 1.82/2.00 meet(converse(complement(converse(complement(join(zero, complement(X)))))), meet(join(zero, complement(X)), top)) 1.82/2.00 = { by lemma 29 } 1.82/2.00 meet(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(X))) 1.82/2.00 = { by lemma 14 } 1.82/2.00 meet(join(zero, complement(X)), converse(complement(converse(complement(join(zero, complement(X))))))) 1.82/2.00 = { by axiom 2 (maddux4_definiton_of_meet_4) } 1.82/2.00 complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X))))))))) 1.82/2.00 = { by lemma 28 } 1.82/2.00 join(zero, complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 13 } 1.82/2.00 join(complement(top), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 39 } 1.82/2.00 join(complement(join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 35 } 1.82/2.00 join(meet(join(zero, complement(X)), complement(converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 1.82/2.00 = { by lemma 21 } 1.82/2.00 join(zero, complement(X)) 1.82/2.00 = { by lemma 28 } 1.82/2.00 complement(X) 1.82/2.00 1.82/2.00 Goal 1 (goals_14): complement(sk1) = join(composition(complement(composition(sk1, sk2)), converse(sk2)), complement(sk1)). 1.82/2.00 Proof: 1.82/2.00 complement(sk1) 1.82/2.00 = { by lemma 43 } 1.82/2.00 converse(complement(converse(sk1))) 1.82/2.00 = { by lemma 18 } 1.82/2.00 converse(join(complement(converse(sk1)), composition(converse(converse(converse(converse(sk2)))), complement(composition(converse(converse(converse(sk2))), converse(sk1)))))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 converse(join(complement(converse(sk1)), composition(converse(converse(sk2)), complement(composition(converse(converse(converse(sk2))), converse(sk1)))))) 1.82/2.00 = { by axiom 10 (converse_multiplicativity_10) } 1.82/2.00 converse(join(complement(converse(sk1)), composition(converse(converse(sk2)), complement(converse(composition(sk1, converse(converse(sk2)))))))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 converse(join(composition(converse(converse(sk2)), complement(converse(composition(sk1, converse(converse(sk2)))))), complement(converse(sk1)))) 1.82/2.00 = { by axiom 11 (converse_additivity_9) } 1.82/2.00 join(converse(composition(converse(converse(sk2)), complement(converse(composition(sk1, converse(converse(sk2))))))), converse(complement(converse(sk1)))) 1.82/2.00 = { by lemma 16 } 1.82/2.00 join(composition(converse(complement(converse(composition(sk1, converse(converse(sk2)))))), converse(sk2)), converse(complement(converse(sk1)))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 join(converse(complement(converse(sk1))), composition(converse(complement(converse(composition(sk1, converse(converse(sk2)))))), converse(sk2))) 1.82/2.00 = { by lemma 43 } 1.82/2.00 join(complement(sk1), composition(converse(complement(converse(composition(sk1, converse(converse(sk2)))))), converse(sk2))) 1.82/2.00 = { by lemma 43 } 1.82/2.00 join(complement(sk1), composition(complement(composition(sk1, converse(converse(sk2)))), converse(sk2))) 1.82/2.00 = { by axiom 5 (converse_idempotence_8) } 1.82/2.00 join(complement(sk1), composition(complement(composition(sk1, sk2)), converse(sk2))) 1.82/2.00 = { by axiom 1 (maddux1_join_commutativity_1) } 1.82/2.00 join(composition(complement(composition(sk1, sk2)), converse(sk2)), complement(sk1)) 1.82/2.00 % SZS output end Proof 1.82/2.00 1.82/2.00 RESULT: Unsatisfiable (the axioms are contradictory). 1.82/2.01 EOF