Copyright (c) 1989 Association of Mizar Users
environ vocabulary TARSKI, BOOLE; notation TARSKI, XBOOLE_0; constructors TARSKI, XBOOLE_0; clusters XBOOLE_0; theorems TARSKI, XBOOLE_0, XBOOLE_1; schemes XBOOLE_0; begin reserve x,x1,x2,x3,x4,x5,x6,x7,x8,y,X,Z for set; scheme UI1{x1()->set,P[set]}: P[x1()] provided A1: for x1 holds P[x1] by A1; scheme UI2{x1, x2()->set,P[set,set]}: P[x1(),x2()] provided A1: for x1,x2 holds P[x1,x2] by A1; scheme UI3{x1, x2, x3()->set,P[set,set,set]}: P[x1(),x2(),x3()] provided A1: for x1,x2,x3 holds P[x1,x2,x3] by A1; scheme UI4{x1, x2, x3, x4()->set,P[set,set,set,set]}: P[x1(),x2(),x3(),x4()] provided A1: for x1,x2,x3,x4 holds P[x1,x2,x3,x4] by A1; scheme UI5 {x1, x2, x3, x4, x5()->set, P[set,set,set,set,set]}: P[x1(),x2(),x3(),x4(),x5()] provided A1: for x1,x2,x3,x4,x5 holds P[x1,x2,x3,x4,x5] by A1; scheme UI6 {x1, x2, x3, x4, x5, x6()->set, P[set,set,set,set,set,set]}: P[x1(),x2(),x3(),x4(),x5(),x6()] provided A1: for x1,x2,x3,x4,x5,x6 holds P[x1,x2,x3,x4,x5,x6] by A1; scheme UI7 {x1, x2, x3, x4, x5, x6, x7()->set, P[set,set,set,set,set,set,set]}: P[x1(),x2(),x3(),x4(),x5(),x6(),x7()] provided A1: for x1,x2,x3,x4,x5,x6,x7 holds P[x1,x2,x3,x4,x5,x6,x7] by A1; scheme UI8 {x1, x2, x3, x4, x5, x6, x7, x8()->set, P[set,set,set,set,set,set,set,set]}: P[x1(),x2(),x3(),x4(),x5(),x6(),x7(),x8()] provided A1: for x1,x2,x3,x4,x5,x6,x7,x8 holds P[x1,x2,x3,x4,x5,x6,x7,x8] by A1 ; scheme UI9 {x1, x2, x3, x4, x5, x6, x7, x8, x9()->set, P[set,set,set,set,set,set,set,set,set]}: P[x1(),x2(),x3(),x4(),x5(),x6(),x7(),x8(),x9()] provided A1: for x1,x2,x3,x4,x5,x6,x7,x8,x9 being set holds P[x1,x2,x3,x4,x5,x6,x7,x8,x9] by A1; Lm1: x in union({X,{y}}) iff x in X or x=y proof A1: x in union({X,{y}}) implies x in X or x in {y} proof assume x in union({X,{y}}); then ex Z st x in Z & Z in {X,{y}} by TARSKI:def 4; hence thesis by TARSKI:def 2; end; A2: X in {X,{y}} & {y} in {X,{y}} by TARSKI:def 2; x in {y} iff x=y by TARSKI:def 1; hence thesis by A1,A2,TARSKI:def 4; end; definition let x1,x2,x3; func { x1,x2,x3 } -> set means :Def1: x in it iff x=x1 or x=x2 or x=x3; existence proof take union({{x1,x2},{x3}}); let x; x in { x1,x2 } iff x = x1 or x = x2 by TARSKI:def 2; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; canceled 12; theorem x in { x1,x2,x3 } implies x=x1 or x=x2 or x=x3 by Def1; theorem x=x1 or x=x2 or x=x3 implies x in { x1,x2,x3 } by Def1; theorem for x1,x2,x3,X st for x holds x in X iff x=x1 or x=x2 or x=x3 holds X = { x1,x2,x3 } by Def1; definition let x1,x2,x3,x4; func { x1,x2,x3,x4 } -> set means :Def2: x in it iff x=x1 or x=x2 or x=x3 or x=x4; existence proof take union({{x1,x2,x3},{x4}}); let x; x in { x1,x2,x3 } iff x = x1 or x = x2 or x = x3 by Def1; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3 or $1=x4; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; Lm2: x in { x1,x2,x3,x4 } iff x=x1 or x=x2 or x=x3 or x = x4 by Def2; canceled 2; theorem x in { x1,x2,x3,x4 } implies x=x1 or x=x2 or x=x3 or x = x4 by Def2; theorem x=x1 or x=x2 or x=x3 or x = x4 implies x in { x1,x2,x3,x4 } by Def2; theorem for x1,x2,x3,x4,X st for x holds x in X iff x=x1 or x=x2 or x=x3 or x = x4 holds X = { x1,x2,x3,x4 } by Def2; definition let x1,x2,x3,x4,x5; func { x1,x2,x3,x4,x5 } -> set means :Def3: x in it iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5; existence proof take union({{x1,x2,x3,x4},{x5}}); let x; x in { x1,x2,x3,x4 } iff x = x1 or x = x2 or x = x3 or x = x4 by Lm2; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3 or $1=x4 or $1=x5; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; Lm3: x in { x1,x2,x3,x4,x5 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 proof defpred P[set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5; A1: for x1,x2,x3,x4,x5 holds P[x1,x2,x3,x4,x5] by Def3; P[x1,x2,x3,x4,x5] from UI5(A1); hence thesis; end; canceled 2; theorem x in { x1,x2,x3,x4,x5 } implies x=x1 or x=x2 or x=x3 or x=x4 or x=x5 by Lm3; theorem x=x1 or x=x2 or x=x3 or x=x4 or x=x5 implies x in { x1,x2,x3,x4,x5 } by Def3; theorem for X being set st for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 holds X = { x1,x2,x3,x4,x5 } by Def3; definition let x1,x2,x3,x4,x5,x6; func { x1,x2,x3,x4,x5,x6 } -> set means :Def4: x in it iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6; existence proof take union({{x1,x2,x3,x4,x5},{x6}}); let x; x in {x1,x2,x3,x4,x5} iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 by Lm3; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3 or $1=x4 or $1=x5 or $1=x6; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; Lm4: x in { x1,x2,x3,x4,x5,x6 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 proof defpred P[set,set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5,$6 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5 or x = $6; A1: for x1,x2,x3,x4,x5,x6 holds P[x1,x2,x3,x4,x5,x6] by Def4; P[x1,x2,x3,x4,x5,x6] from UI6(A1); hence thesis; end; canceled 2; theorem x in { x1,x2,x3,x4,x5,x6 } implies x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 proof x in { x1,x2,x3,x4,x5,x6 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 by Lm4; hence thesis; end; theorem x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 implies x in { x1,x2,x3,x4,x5,x6 } by Lm4; theorem for X being set st for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 holds X = { x1,x2,x3,x4,x5,x6 } by Def4; definition let x1,x2,x3,x4,x5,x6,x7; func { x1,x2,x3,x4,x5,x6,x7 } -> set means :Def5: x in it iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7; existence proof take union({{x1,x2,x3,x4,x5,x6},{x7}}); let x; x in { x1,x2,x3,x4,x5,x6 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 by Lm4; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3 or $1=x4 or $1=x5 or $1=x6 or $1=x7; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; Lm5: for x1,x2,x3,x4,x5,x6,x7 for X being set holds X = { x1,x2,x3,x4,x5,x6,x7 } iff for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 proof defpred P[set,set,set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5,$6,$7 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5 or x = $6 or x = $7; A1: for x1,x2,x3,x4,x5,x6,x7 holds P[x1,x2,x3,x4,x5,x6,x7] by Def5; let x1,x2,x3,x4,x5,x6,x7; P[x1,x2,x3,x4,x5,x6,x7] from UI7(A1); hence thesis; end; Lm6: x in { x1,x2,x3,x4,x5,x6,x7 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 proof defpred P[set,set,set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5,$6,$7 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5 or x = $6 or x = $7; A1: for x1,x2,x3,x4,x5,x6,x7 holds P[x1,x2,x3,x4,x5,x6,x7] by Def5; P[x1,x2,x3,x4,x5,x6,x7] from UI7(A1); hence thesis; end; canceled 2; theorem x in { x1,x2,x3,x4,x5,x6,x7 } implies x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 proof x in { x1,x2,x3,x4,x5,x6,x7 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 by Lm6; hence thesis; end; theorem x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 implies x in { x1,x2,x3,x4,x5,x6,x7 } by Lm6; theorem for X being set st for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 holds X = { x1,x2,x3,x4,x5,x6,x7 } by Lm5; definition let x1,x2,x3,x4,x5,x6,x7,x8; func { x1,x2,x3,x4,x5,x6,x7,x8 } -> set means :Def6: x in it iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8; existence proof take union({{x1,x2,x3,x4,x5,x6,x7},{x8}}); let x; x in { x1,x2,x3,x4,x5,x6,x7 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x = x6 or x=x7 by Lm6; hence thesis by Lm1; end; uniqueness proof defpred P[set] means $1=x1 or $1=x2 or $1=x3 or $1=x4 or $1=x5 or $1=x6 or $1=x7 or $1=x8; for X1,X2 being set st (for x being set holds x in X1 iff P[x]) & (for x being set holds x in X2 iff P[x]) holds X1 = X2 from SetEq; hence thesis; end; end; Lm7: for x1,x2,x3,x4,x5,x6,x7,x8 for X being set holds X = { x1,x2,x3,x4,x5,x6,x7,x8 } iff for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 proof defpred P[set,set,set,set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5,$6,$7,$8 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5 or x = $6 or x = $7 or x = $8; A1: for x1,x2,x3,x4,x5,x6,x7,x8 holds P[x1,x2,x3,x4,x5,x6,x7,x8] by Def6; let x1,x2,x3,x4,x5,x6,x7,x8; P[x1,x2,x3,x4,x5,x6,x7,x8] from UI8(A1); hence thesis; end; Lm8: x in { x1,x2,x3,x4,x5,x6,x7,x8 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 proof defpred P[set,set,set,set,set,set,set,set] means for X being set holds X = { $1,$2,$3,$4,$5,$6,$7,$8 } iff for x holds x in X iff x=$1 or x=$2 or x=$3 or x=$4 or x=$5 or x = $6 or x = $7 or x = $8; A1: for x1,x2,x3,x4,x5,x6,x7,x8 holds P[x1,x2,x3,x4,x5,x6,x7,x8] by Def6; P[x1,x2,x3,x4,x5,x6,x7,x8] from UI8(A1); hence thesis; end; canceled 2; theorem x in { x1,x2,x3,x4,x5,x6,x7,x8 } implies x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 proof x in { x1,x2,x3,x4,x5,x6,x7,x8 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 by Lm8; hence thesis; end; theorem x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 implies x in { x1,x2,x3,x4,x5,x6,x7,x8 } by Lm8; theorem for X being set st for x holds x in X iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 holds X = { x1,x2,x3,x4,x5,x6,x7,x8 } by Lm7; theorem Th41: { x1,x2 } = { x1 } \/ { x2 } proof now let x; x in { x1,x2 } iff x=x1 or x=x2 by TARSKI:def 2; then x in { x1,x2 } iff x in { x1 } or x in { x2 } by TARSKI:def 1; hence x in { x1,x2 } iff x in { x1 } \/ { x2 } by XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th42: { x1,x2,x3 } = { x1 } \/ { x2,x3 } proof now let x; x in { x1,x2,x3 } iff x=x1 or x=x2 or x=x3 by Def1; then x in { x1,x2,x3 } iff x in { x1 } or x in { x2,x3 } by TARSKI:def 1, def 2; hence x in { x1,x2,x3 } iff x in { x1 } \/ { x2,x3 } by XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th43: { x1,x2,x3 } = { x1,x2 } \/ { x3 } proof thus { x1,x2,x3 } = { x1 } \/ { x2,x3 } by Th42 .= { x1 } \/ ({ x2 } \/ { x3 }) by Th41 .= { x1 } \/ { x2 } \/ { x3 } by XBOOLE_1:4 .= { x1,x2 } \/ { x3 } by Th41; end; Lm9: { x1,x2,x3,x4 } = { x1,x2 } \/ { x3,x4 } proof now let x; x in { x1,x2,x3,x4 } iff x=x1 or x=x2 or x=x3 or x=x4 by Lm2; then x in { x1,x2,x3,x4 } iff x in { x1,x2 } or x in { x3,x4 } by TARSKI:def 2; hence x in { x1,x2,x3,x4 } iff x in { x1,x2 } \/ { x3,x4 } by XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th44: { x1,x2,x3,x4 } = { x1 } \/ { x2,x3,x4 } proof thus { x1,x2,x3,x4 } = { x1,x2 } \/ { x3,x4 } by Lm9 .= { x1 } \/ { x2 } \/ { x3,x4 } by Th41 .= { x1 } \/ ({ x2 } \/ { x3,x4 }) by XBOOLE_1:4 .= { x1 } \/ { x2,x3,x4 } by Th42; end; theorem { x1,x2,x3,x4 } = { x1,x2 } \/ { x3,x4 } by Lm9; theorem Th46: { x1,x2,x3,x4 } = { x1,x2,x3 } \/ { x4 } proof thus { x1,x2,x3,x4 } = { x1,x2 } \/ { x3,x4 } by Lm9 .= { x1,x2 } \/ ({ x3 } \/ { x4 }) by Th41 .= { x1,x2 } \/ { x3 } \/ { x4 } by XBOOLE_1:4 .= { x1,x2,x3 } \/ { x4 } by Th43; end; Lm10: { x1,x2,x3,x4,x5 } = { x1,x2,x3 } \/ { x4,x5 } proof now let x; x in { x1,x2,x3,x4,x5 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 by Lm3; then x in { x1,x2,x3,x4,x5 } iff x in { x1,x2,x3 } or x in { x4,x5 } by Def1,TARSKI:def 2; hence x in { x1,x2,x3,x4,x5 } iff x in { x1,x2,x3 } \/ { x4,x5 } by XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th47: { x1,x2,x3,x4,x5 } = { x1 } \/ { x2,x3,x4,x5 } proof thus { x1,x2,x3,x4,x5 } = { x1,x2,x3 } \/ { x4,x5 } by Lm10 .= { x1 } \/ { x2,x3 } \/ { x4,x5 } by Th42 .= { x1 } \/ ({ x2,x3 } \/ { x4,x5 }) by XBOOLE_1:4 .= { x1 } \/ { x2,x3,x4,x5 } by Lm9; end; theorem Th48: { x1,x2,x3,x4,x5 } = { x1,x2 } \/ { x3,x4,x5 } proof thus { x1,x2,x3,x4,x5 } = { x1,x2,x3 } \/ { x4,x5 } by Lm10 .= { x1,x2 } \/ { x3 } \/ { x4,x5 } by Th43 .= { x1,x2 } \/ ({ x3 } \/ { x4,x5 }) by XBOOLE_1:4 .= { x1,x2 } \/ { x3,x4,x5 } by Th42; end; theorem { x1,x2,x3,x4,x5 } = { x1,x2,x3 } \/ { x4,x5 } by Lm10; theorem Th50: { x1,x2,x3,x4,x5 } = { x1,x2,x3,x4 } \/ { x5 } proof thus { x1,x2,x3,x4,x5 } = { x1,x2,x3 } \/ { x4,x5 } by Lm10 .= { x1,x2,x3 } \/ ({ x4 } \/ { x5 }) by Th41 .= { x1,x2,x3 } \/ { x4 } \/ { x5 } by XBOOLE_1:4 .= { x1,x2,x3,x4 } \/ { x5 } by Th46; end; Lm11: { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } proof now let x; x in { x1,x2,x3,x4,x5,x6 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 by Lm4; then x in { x1,x2,x3,x4,x5,x6 } iff x in { x1,x2,x3 } or x in { x4,x5,x6 } by Def1; hence x in { x1,x2,x3,x4,x5,x6 } iff x in { x1,x2,x3 } \/ { x4,x5,x6 } by XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th51: { x1,x2,x3,x4,x5,x6 } = { x1 } \/ { x2,x3,x4,x5,x6 } proof thus { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } by Lm11 .= { x1 } \/ { x2,x3 } \/ { x4,x5,x6 } by Th42 .= { x1 } \/ ({ x2,x3 } \/ { x4,x5,x6 }) by XBOOLE_1:4 .= { x1 } \/ { x2,x3,x4,x5,x6 } by Th48; end; theorem Th52: { x1,x2,x3,x4,x5,x6 } = { x1,x2 } \/ { x3,x4,x5,x6 } proof thus { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } by Lm11 .= { x1,x2 } \/ { x3 } \/ { x4,x5,x6 } by Th43 .= { x1,x2 } \/ ({ x3 } \/ { x4,x5,x6 }) by XBOOLE_1:4 .= { x1,x2 } \/ { x3,x4,x5,x6 } by Th44; end; theorem { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } by Lm11; theorem Th54: { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3,x4 } \/ { x5,x6 } proof thus { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } by Lm11 .= { x1,x2,x3 } \/ ({ x4 } \/ { x5,x6 }) by Th42 .= { x1,x2,x3 } \/ { x4 } \/ { x5,x6 } by XBOOLE_1:4 .= { x1,x2,x3,x4 } \/ { x5,x6 } by Th46; end; theorem { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3,x4,x5 } \/ { x6 } proof thus { x1,x2,x3,x4,x5,x6 } = { x1,x2,x3 } \/ { x4,x5,x6 } by Lm11 .= { x1,x2,x3 } \/ ({ x4,x5 } \/ { x6 }) by Th43 .= { x1,x2,x3 } \/ { x4,x5 } \/ { x6 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5 } \/ { x6 } by Lm10; end; Lm12: { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } proof now let x; A1: x in { x1,x2,x3,x4 } iff x=x1 or x=x2 or x=x3 or x=x4 by Lm2; A2: x in { x5,x6,x7 } iff x=x5 or x=x6 or x=x7 by Def1; x in { x1,x2,x3,x4,x5,x6,x7 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 by Lm6; hence x in { x1,x2,x3,x4,x5,x6,x7 } iff x in { x1,x2,x3,x4 } \/ { x5,x6,x7 } by A1,A2,XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem Th56: { x1,x2,x3,x4,x5,x6,x7 } = { x1 } \/ { x2,x3,x4,x5,x6,x7 } proof thus { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12 .= { x1 } \/ { x2,x3,x4 } \/ { x5,x6,x7 } by Th44 .= { x1 } \/ ({ x2,x3,x4 } \/ { x5,x6,x7 }) by XBOOLE_1:4 .= { x1 } \/ { x2,x3,x4,x5,x6,x7 } by Lm11; end; theorem Th57: { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2 } \/ { x3,x4,x5,x6,x7 } proof thus { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12 .= { x1,x2 } \/ { x3,x4 } \/ { x5,x6,x7 } by Lm9 .= { x1,x2 } \/ ({ x3,x4 } \/ { x5,x6,x7 }) by XBOOLE_1:4 .= { x1,x2 } \/ { x3,x4,x5,x6,x7 } by Th48; end; theorem Th58: { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3 } \/ { x4,x5,x6,x7 } proof thus { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12 .= { x1,x2,x3 } \/ { x4 } \/ { x5,x6,x7 } by Th46 .= { x1,x2,x3 } \/ ({ x4 } \/ { x5,x6,x7 }) by XBOOLE_1:4 .= { x1,x2,x3 } \/ { x4,x5,x6,x7 } by Th44; end; theorem { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12; theorem { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4,x5 } \/ { x6,x7 } proof thus { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12 .= { x1,x2,x3,x4 } \/ ({ x5 } \/ { x6,x7 }) by Th42 .= { x1,x2,x3,x4 } \/ { x5 } \/ { x6,x7 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5 } \/ { x6,x7 } by Th50; end; theorem { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4,x5,x6 } \/ { x7 } proof thus { x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4 } \/ { x5,x6,x7 } by Lm12 .= { x1,x2,x3,x4 } \/ ({ x5,x6 } \/ { x7 }) by Th43 .= { x1,x2,x3,x4 } \/ { x5,x6 } \/ { x7 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5,x6 } \/ { x7 } by Th54; end; Lm13: { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } proof now let x; A1: x in { x1,x2,x3,x4 } iff x=x1 or x=x2 or x=x3 or x=x4 by Lm2; A2: x in { x5,x6,x7,x8 } iff x=x5 or x=x6 or x=x7 or x=x8 by Lm2; x in { x1,x2,x3,x4,x5,x6,x7,x8 } iff x=x1 or x=x2 or x=x3 or x=x4 or x=x5 or x=x6 or x=x7 or x=x8 by Lm8; hence x in { x1,x2,x3,x4,x5,x6,x7,x8 } iff x in { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by A1,A2,XBOOLE_0:def 2; end; hence thesis by TARSKI:2; end; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1 } \/ { x2,x3,x4,x5,x6,x7,x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1 } \/ { x2,x3,x4 } \/ { x5,x6,x7,x8 } by Th44 .= { x1 } \/ ({ x2,x3,x4 } \/ { x5,x6,x7,x8 }) by XBOOLE_1:4 .= { x1 } \/ { x2,x3,x4,x5,x6,x7,x8 } by Th58; end; theorem Th63: { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2 } \/ { x3,x4,x5,x6,x7,x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1,x2 } \/ { x3,x4 } \/ { x5,x6,x7,x8 } by Lm9 .= { x1,x2 } \/ ({ x3,x4 } \/ { x5,x6,x7,x8 }) by XBOOLE_1:4 .= { x1,x2 } \/ { x3,x4,x5,x6,x7,x8 } by Th52; end; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3 } \/ { x4,x5,x6,x7,x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1,x2,x3 } \/ { x4 } \/ { x5,x6,x7,x8 } by Th46 .= { x1,x2,x3 } \/ ({ x4 } \/ { x5,x6,x7,x8 }) by XBOOLE_1:4 .= { x1,x2,x3 } \/ { x4,x5,x6,x7,x8 } by Th47; end; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4,x5 } \/ { x6,x7,x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1,x2,x3,x4 } \/ ({x5 } \/ { x6,x7,x8 }) by Th44 .= { x1,x2,x3,x4 } \/ {x5 } \/ { x6,x7,x8 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5 } \/ { x6,x7,x8 } by Th50; end; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4,x5,x6 } \/ { x7,x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1,x2,x3,x4 } \/ ({ x5,x6 } \/ { x7,x8 }) by Lm9 .= { x1,x2,x3,x4 } \/ { x5,x6 } \/ { x7,x8 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5,x6 } \/ { x7,x8 } by Th54; end; theorem { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4,x5,x6,x7 } \/ { x8 } proof thus { x1,x2,x3,x4,x5,x6,x7,x8 } = { x1,x2,x3,x4 } \/ { x5,x6,x7,x8 } by Lm13 .= { x1,x2,x3,x4 } \/ ({ x5,x6,x7 } \/ { x8 }) by Th46 .= { x1,x2,x3,x4 } \/ { x5,x6,x7 } \/ { x8 } by XBOOLE_1:4 .= { x1,x2,x3,x4,x5,x6,x7 } \/ { x8 } by Lm12; end; theorem Th69: { x1,x1 } = { x1 } proof now let x; x in { x1,x1 } iff x = x1 by TARSKI:def 2; hence x in { x1,x1 } iff x in { x1 } by TARSKI:def 1; end; hence thesis by TARSKI:2; end; theorem Th70: { x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x2 } = { x1,x1 } \/ { x2 } by Th43 .= { x1 } \/ { x2 } by Th69 .= { x1,x2 } by Th41; end; theorem Th71: { x1,x1,x2,x3 } = { x1,x2,x3 } proof thus { x1,x1,x2,x3 } = { x1,x1 } \/ { x2,x3 } by Lm9 .= { x1 } \/ { x2,x3 } by Th69 .= { x1,x2,x3 } by Th42; end; theorem Th72: { x1,x1,x2,x3,x4 } = { x1,x2,x3,x4 } proof thus { x1,x1,x2,x3,x4 } = { x1,x1 } \/ { x2,x3,x4 } by Th48 .= { x1 } \/ { x2,x3,x4 } by Th69 .= { x1,x2,x3,x4 } by Th44; end; theorem Th73: { x1,x1,x2,x3,x4,x5 } = { x1,x2,x3,x4,x5 } proof thus { x1,x1,x2,x3,x4,x5 } = { x1,x1 } \/ { x2,x3,x4,x5 } by Th52 .= { x1 } \/ { x2,x3,x4,x5 } by Th69 .= { x1,x2,x3,x4,x5 } by Th47; end; theorem Th74: { x1,x1,x2,x3,x4,x5,x6 } = { x1,x2,x3,x4,x5,x6 } proof thus { x1,x1,x2,x3,x4,x5,x6 } = { x1,x1 } \/ { x2,x3,x4,x5,x6 } by Th57 .= { x1 } \/ { x2,x3,x4,x5,x6 } by Th69 .= { x1,x2,x3,x4,x5,x6 } by Th51; end; theorem Th75: { x1,x1,x2,x3,x4,x5,x6,x7 } = { x1,x2,x3,x4,x5,x6,x7 } proof thus { x1,x1,x2,x3,x4,x5,x6,x7 } = { x1,x1 } \/ { x2,x3,x4,x5,x6,x7 } by Th63 .= { x1 } \/ { x2,x3,x4,x5,x6,x7 } by Th69 .= { x1,x2,x3,x4,x5,x6,x7 } by Th56; end; theorem { x1,x1,x1 } = { x1 } proof thus { x1,x1,x1 } = { x1,x1 } by Th70 .= { x1 } by Th69; end; theorem Th77: { x1,x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x1,x2 } = { x1,x1,x2 } by Th71 .= { x1,x2 } by Th70; end; theorem Th78: { x1,x1,x1,x2,x3 } = { x1,x2,x3 } proof thus { x1,x1,x1,x2,x3 } = { x1,x1,x2,x3 } by Th72 .= { x1,x2,x3 } by Th71; end; theorem Th79: { x1,x1,x1,x2,x3,x4 } = { x1,x2,x3,x4 } proof thus { x1,x1,x1,x2,x3,x4 } = { x1,x1,x2,x3,x4 } by Th73 .= { x1,x2,x3,x4 } by Th72; end; theorem Th80: { x1,x1,x1,x2,x3,x4,x5 } = { x1,x2,x3,x4,x5 } proof thus { x1,x1,x1,x2,x3,x4,x5 } = { x1,x1,x2,x3,x4,x5 } by Th74 .= { x1,x2,x3,x4,x5 } by Th73; end; theorem Th81: { x1,x1,x1,x2,x3,x4,x5,x6 } = { x1,x2,x3,x4,x5,x6 } proof thus { x1,x1,x1,x2,x3,x4,x5,x6 } = { x1,x1,x2,x3,x4,x5,x6 } by Th75 .= { x1,x2,x3,x4,x5,x6 } by Th74; end; theorem { x1,x1,x1,x1 } = { x1 } proof thus { x1,x1,x1,x1 } = { x1,x1 } by Th77 .= { x1 } by Th69; end; theorem Th83: { x1,x1,x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x1,x1,x2 } = { x1,x1,x2 } by Th78 .= { x1,x2 } by Th70; end; theorem Th84: { x1,x1,x1,x1,x2,x3 } = { x1,x2,x3 } proof thus { x1,x1,x1,x1,x2,x3 } = { x1,x1,x2,x3 } by Th79 .= { x1,x2,x3 } by Th71; end; theorem Th85: { x1,x1,x1,x1,x2,x3,x4 } = { x1,x2,x3,x4 } proof thus { x1,x1,x1,x1,x2,x3,x4 } = { x1,x1,x2,x3,x4 } by Th80 .= { x1,x2,x3,x4 } by Th72; end; theorem Th86: { x1,x1,x1,x1,x2,x3,x4,x5 } = { x1,x2,x3,x4,x5 } proof thus { x1,x1,x1,x1,x2,x3,x4,x5 } = { x1,x1,x2,x3,x4,x5 } by Th81 .= { x1,x2,x3,x4,x5 } by Th73; end; theorem { x1,x1,x1,x1,x1 } = { x1 } proof thus { x1,x1,x1,x1,x1 } = { x1,x1 } by Th83 .= { x1 } by Th69; end; theorem Th88: { x1,x1,x1,x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x1,x1,x1,x2 } = { x1,x1,x2 } by Th84 .= { x1,x2 } by Th70; end; theorem Th89: { x1,x1,x1,x1,x1,x2,x3 } = { x1,x2,x3 } proof thus { x1,x1,x1,x1,x1,x2,x3 } = { x1,x1,x2,x3 } by Th85 .= { x1,x2,x3 } by Th71; end; theorem Th90: { x1,x1,x1,x1,x1,x2,x3,x4 } = { x1,x2,x3,x4 } proof thus { x1,x1,x1,x1,x1,x2,x3,x4 } = { x1,x1,x2,x3,x4 } by Th86 .= { x1,x2,x3,x4 } by Th72; end; theorem { x1,x1,x1,x1,x1,x1 } = { x1 } proof thus { x1,x1,x1,x1,x1,x1 } = { x1,x1 } by Th88 .= { x1 } by Th69; end; theorem Th92: { x1,x1,x1,x1,x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x1,x1,x1,x1,x2 } = { x1,x1,x2 } by Th89 .= { x1,x2 } by Th70; end; theorem Th93: { x1,x1,x1,x1,x1,x1,x2,x3 } = { x1,x2,x3 } proof thus { x1,x1,x1,x1,x1,x1,x2,x3 } = { x1,x1,x2,x3 } by Th90 .= { x1,x2,x3 } by Th71; end; theorem { x1,x1,x1,x1,x1,x1,x1 } = { x1 } proof thus { x1,x1,x1,x1,x1,x1,x1 } = { x1,x1 } by Th92 .= { x1 } by Th69; end; theorem Th95: { x1,x1,x1,x1,x1,x1,x1,x2 } = { x1,x2 } proof thus { x1,x1,x1,x1,x1,x1,x1,x2 } = { x1,x1,x2 } by Th93 .= { x1,x2 } by Th70; end; theorem { x1,x1,x1,x1,x1,x1,x1,x1 } = { x1 } proof thus { x1,x1,x1,x1,x1,x1,x1,x1 } = { x1,x1 } by Th95 .= { x1 } by Th69; end; canceled; theorem Th98: { x1,x2,x3 } = { x1,x3,x2 } proof thus { x1,x2,x3 } = { x1 } \/ { x2,x3 } by Th42 .= { x1,x3,x2 } by Th42; end; theorem Th99: { x1,x2,x3 } = { x2,x1,x3 } proof thus { x1,x2,x3 } = { x1,x2 } \/ { x3 } by Th43 .= { x2,x1,x3 } by Th43; end; theorem Th100: { x1,x2,x3 } = { x2,x3,x1 } proof thus { x1,x2,x3 } = { x2,x3 } \/ { x1 } by Th42 .= { x2,x3,x1 } by Th43; end; canceled; theorem Th102: { x1,x2,x3 } = { x3,x2,x1 } proof thus { x1,x2,x3 } = { x3,x1,x2 } by Th100 .= { x3,x2,x1 } by Th98; end; theorem Th103: { x1,x2,x3,x4 } = { x1,x2,x4,x3 } proof thus { x1,x2,x3,x4 } = { x1 } \/ { x2,x3,x4 } by Th44 .= { x1 } \/ { x2,x4,x3 } by Th98 .= { x1,x2,x4,x3 } by Th44; end; theorem { x1,x2,x3,x4 } = { x1,x3,x2,x4 } proof thus { x1,x2,x3,x4 } = { x1 } \/ { x2,x3,x4 } by Th44 .= { x1 } \/ { x3,x2,x4 } by Th99 .= { x1,x3,x2,x4 } by Th44; end; theorem Th105: { x1,x2,x3,x4 } = { x1,x3,x4,x2 } proof thus { x1,x2,x3,x4 } = { x1 } \/ { x2,x3,x4 } by Th44 .= { x1 } \/ { x3,x4,x2 } by Th100 .= { x1,x3,x4,x2 } by Th44; end; canceled; theorem Th107: { x1,x2,x3,x4 } = { x1,x4,x3,x2 } proof thus { x1,x2,x3,x4 } = { x1 } \/ { x2,x3,x4 } by Th44 .= { x1 } \/ { x4,x3,x2 } by Th102 .= { x1,x4,x3,x2 } by Th44; end; theorem Th108: { x1,x2,x3,x4 } = { x2,x1,x3,x4 } proof thus { x1,x2,x3,x4 } = { x1,x2,x3 } \/ { x4 } by Th46 .= { x2,x1,x3 } \/ { x4 } by Th99 .= { x2,x1,x3,x4 } by Th46; end; Lm14: { x1,x2,x3,x4 } = { x2,x3,x1,x4 } proof thus { x1,x2,x3,x4 } = { x1,x2,x3 } \/ { x4 } by Th46 .= { x2,x3,x1 } \/ { x4 } by Th100 .= { x2,x3,x1,x4 } by Th46; end; theorem { x1,x2,x3,x4 } = { x2,x1,x4,x3 } proof thus { x1,x2,x3,x4 } = { x2,x3,x1,x4 } by Lm14 .= { x2,x1,x4,x3 } by Th105; end; theorem { x1,x2,x3,x4 } = { x2,x3,x1,x4 } by Lm14; theorem { x1,x2,x3,x4 } = { x2,x3,x4,x1 } proof thus { x1,x2,x3,x4 } = { x2,x3,x1,x4 } by Lm14 .= { x2,x3,x4,x1 } by Th103; end; theorem { x1,x2,x3,x4 } = { x2,x4,x1,x3 } proof thus { x1,x2,x3,x4 } = { x2,x3,x1,x4 } by Lm14 .= { x2,x4,x1,x3 } by Th107; end; theorem { x1,x2,x3,x4 } = { x2,x4,x3,x1 } proof thus { x1,x2,x3,x4 } = { x2,x3,x1,x4 } by Lm14 .= { x2,x4,x3,x1 } by Th105; end; Lm15: { x1,x2,x3,x4 } = { x3,x2,x1,x4 } proof thus { x1,x2,x3,x4 } = { x1,x2,x3 } \/ { x4 } by Th46 .= { x3,x2,x1 } \/ { x4 } by Th102 .= { x3,x2,x1,x4 } by Th46; end; canceled 2; theorem { x1,x2,x3,x4 } = { x3,x2,x1,x4 } by Lm15; theorem { x1,x2,x3,x4 } = { x3,x2,x4,x1 } proof thus { x1,x2,x3,x4 } = { x3,x2,x1,x4 } by Lm15 .= { x3,x2,x4,x1 } by Th103; end; theorem { x1,x2,x3,x4 } = { x3,x4,x1,x2 } proof thus { x1,x2,x3,x4 } = { x3,x2,x1,x4 } by Lm15 .= { x3,x4,x1,x2 } by Th107; end; theorem Th119: { x1,x2,x3,x4 } = { x3,x4,x2,x1 } proof thus { x1,x2,x3,x4 } = { x3,x2,x1,x4 } by Lm15 .= { x3,x4,x2,x1 } by Th105; end; canceled 3; theorem { x1,x2,x3,x4 } = { x4,x2,x3,x1 } proof thus { x1,x2,x3,x4 } = { x3,x4,x2,x1 } by Th119 .= { x4,x2,x3,x1 } by Lm14; end; canceled; theorem { x1,x2,x3,x4 } = { x4,x3,x2,x1 } proof thus { x1,x2,x3,x4 } = { x3,x4,x2,x1 } by Th119 .= { x4,x3,x2,x1 } by Th108; end;