Copyright (c) 1995 Association of Mizar Users
environ vocabulary FUNCT_1, SUPINF_1, RLVECT_1, SUPINF_2, ORDINAL2, RELAT_1, ARYTM_3, TARSKI, MEASURE5, FUNCT_2, BOOLE, COMPLEX1, FUNCT_3, MCART_1, MEASURE4, MEASURE1, MEASURE3, MEASURE7; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, MCART_1, NUMBERS, XREAL_0, REAL_1, RELAT_1, FUNCT_1, NAT_1, SUPINF_1, SUPINF_2, MEASURE1, MEASURE3, MEASURE4, MEASURE5, FUNCT_2, DTCONSTR; constructors NAT_1, SUPINF_2, MEASURE3, MEASURE4, MEASURE6, DTCONSTR, MCART_1, FRAENKEL, MEMBERED, XBOOLE_0; clusters SUBSET_1, SUPINF_1, MEASURE4, RELSET_1, ARYTM_3, FRAENKEL, FUNCT_2, MEMBERED, ZFMISC_1, XBOOLE_0, ORDINAL2; requirements NUMERALS, BOOLE, SUBSET, ARITHM; definitions TARSKI, SUPINF_1, MEASURE4, XBOOLE_0; theorems AXIOMS, TARSKI, SUPINF_1, SUPINF_2, MEASURE1, FUNCT_1, MEASURE4, MEASURE5, MEASURE6, ZFMISC_1, FUNCT_2, NAT_1, DTCONSTR, MCART_1, XBOOLE_0, XBOOLE_1, XCMPLX_1; schemes FUNCT_2, NAT_1, COMPLSP1, SUBSET_1, XBOOLE_0; begin :: Some theorems about series of R_eal numbers theorem Th1: for F being Function of NAT,ExtREAL st for n being Nat holds F.n = 0. holds SUM(F) = 0. proof let F be Function of NAT,ExtREAL; assume A1:for n being Nat holds F.n = 0.; defpred P[Nat] means Ser(F).$1 = 0.; Ser(F).0 = F.0 by SUPINF_2:63 .= 0. by A1; then A2: P[0]; A3: for t being Nat st P[t] holds P[t+1] proof let t be Nat; assume Ser(F).t = 0.; hence Ser(F).(t+1) = 0. + F.(t+1) by SUPINF_2:63 .= F.(t+1) by SUPINF_2:18 .= 0. by A1; end; A4:for s being Nat holds P[s] from Ind(A2,A3); A5:sup {0.} = 0. by SUPINF_1:85; rng Ser(F) = {0.} proof A6:dom Ser(F) = NAT & rng Ser(F) c= ExtREAL by FUNCT_2:def 1; thus rng Ser(F) c= {0.} proof let x be set; assume x in rng Ser(F); then consider s being set such that A7:s in dom Ser(F) & x = Ser(F).s by FUNCT_1:def 5; reconsider s as Nat by A7,FUNCT_2:def 1; Ser(F).s = 0. by A4; hence thesis by A7,TARSKI:def 1; end; let x be set; assume x in {0.}; then x = 0. by TARSKI:def 1; then x = Ser(F).0 by A4; hence thesis by A6,FUNCT_1:def 5; end; hence thesis by A5,SUPINF_2:def 23; end; theorem Th2: for F being Function of NAT,ExtREAL st F is nonnegative holds for n being Nat holds F.n <=' Ser(F).n proof let F be Function of NAT,ExtREAL; assume A1:F is nonnegative; let n be Nat; per cases; suppose n = 0; hence thesis by SUPINF_2:63; suppose n <> 0; then consider k being Nat such that A2:n = k + 1 by NAT_1:22; A3:Ser(F).n = Ser(F).k + F.n by A2,SUPINF_2:63; 0. <=' Ser(F).k & F.n <=' F.n & 0. <=' F.n by A1,SUPINF_2:58,59; then not ((0. = +infty & F.n = -infty) or (0. = -infty & F.n = +infty )) & not ((Ser(F).k = +infty & F.n = -infty) or (Ser(F).k = -infty & F.n = +infty)) & 0. <=' Ser(F).k & F.n <=' F.n by SUPINF_1:17,SUPINF_2:def 1; then 0. + F.n <=' Ser(F).n by A3,SUPINF_2:14; hence thesis by SUPINF_2:18; end; theorem Th3: for F,G,H being Function of NAT,ExtREAL st G is nonnegative & H is nonnegative holds (for n being Nat holds F.n = G.n + H.n ) implies (for n being Nat holds (Ser F).n = (Ser G).n + (Ser H).n ) proof let F,G,H be Function of NAT,ExtREAL; assume A1:G is nonnegative & H is nonnegative; assume A2:for n being Nat holds F.n = G.n + H.n; defpred P[Nat] means (Ser F).$1 = (Ser G).$1 + (Ser H).$1; (Ser F).0 = F.0 & (Ser G).0 = G.0 & (Ser H).0 = H.0 by SUPINF_2:63; then A3: P[0] by A2; A4: for k being Nat st P[k] holds P[k+1] proof let k be Nat; assume A5:(Ser F).k = (Ser G).k + (Ser H).k; A6:F.(k+1) = G.(k+1) + H.(k+1) by A2; A7: Ser(G).(k + 1) = Ser(G).k + G.(k + 1) & Ser(H).(k + 1) = Ser(H).k + H.(k + 1) by SUPINF_2:63; set n = k+1; 0. <=' G.n & 0. <=' H.n by A1,SUPINF_2:58; then 0. + 0. <=' G.n + H.n by MEASURE1:4; then 0. <=' G.n + H.n by SUPINF_2:18; then A8: 0. <=' F.(k+1) by A2; A9:0. <=' (Ser G).k & 0. <=' (Ser H).k & 0. <=' (Ser G).(k+1) by A1,SUPINF_2:59; A10:0. <=' H.(k+1) & 0. <=' G.(k+1) by A1,SUPINF_2:58; (Ser G).k + (Ser H).k + F.(k + 1) = ((Ser G).k + F.(k+1)) + (Ser H).k by A8,A9,MEASURE4:1 .= (((Ser G).k + G.(k+1)) + H.(k+1)) + (Ser H).k by A6,A9,A10,MEASURE4:1 .= (Ser G).(k+1) + (Ser H).(k+1) by A7,A9,A10,MEASURE4:1; hence thesis by A5,SUPINF_2:63; end; thus for k being Nat holds P[k] from Ind(A3,A4); end; theorem Th4: for F,G,H being Function of NAT,ExtREAL st for n being Nat holds F.n = G.n + H.n holds G is nonnegative & H is nonnegative implies SUM(F) <=' SUM(G) + SUM(H) proof let F,G,H be Function of NAT,ExtREAL; assume A1:for n being Nat holds F.n = G.n + H.n; assume A2:G is nonnegative & H is nonnegative; defpred P[Nat] means Ser(F).$1 = Ser(G).$1 + Ser(H).$1; A3: P[0] proof Ser(F).0 = F.0 & Ser(G).0 = G.0 & Ser(H).0 = H.0 by SUPINF_2:63; hence thesis by A1; end; A4: for k being Nat st P[k] holds P[k+1] proof let k be Nat; assume A5:Ser(F).k = Ser(G).k + Ser(H).k; A6:Ser(F).(k+1) = Ser(F).k + F.(k+1) & Ser(G).(k+1) = Ser(G).k + G.(k+1) & Ser(H).(k+1) = Ser(H).k + H.(k+1) by SUPINF_2:63; 0. <=' G.(k+1) & 0. <=' H.(k+1) by A2,SUPINF_2:58; then 0. + 0. <=' G.(k+1) + H.(k+1) by MEASURE1:4; then 0. <=' G.(k+1) + H.(k+1) by SUPINF_2:18; then A7: 0. <=' F.(k+1) by A1; A8:0. <=' Ser(G).k & 0. <=' G.(k+1) & 0. <=' Ser(H).k & 0. <=' H.(k+1) & 0. <=' Ser(H).(k+1) by A2,SUPINF_2:58,59; hence Ser(F).(k+1) = Ser(G).k + (Ser(H).k + F.(k+1)) by A5,A6,A7,MEASURE4:1 .= Ser(G).k + (Ser(H).k + (G.(k+1) + H.(k+1))) by A1 .= Ser(G).k + ((Ser(H).k + H.(k+1)) + G.(k+1)) by A8,MEASURE4:1 .= Ser(G).(k+1) + Ser(H).(k+1) by A6,A8,MEASURE4:1; end; A9:for n being Nat holds P[n] from Ind(A3,A4); SUM(G) + SUM(H) is majorant of rng Ser(F) proof let x be R_eal; assume A10:x in rng Ser(F); dom Ser(F) = NAT by FUNCT_2:def 1; then consider n being set such that A11:n in NAT & x = Ser(F).n by A10,FUNCT_1:def 5; reconsider n as Nat by A11; Ser(G).n in rng Ser(G) & Ser(H).n in rng Ser(H) by FUNCT_2:6; then Ser(G).n <=' sup(rng Ser(G)) & Ser(H).n <=' sup(rng Ser(H)) by SUPINF_1:76; then A12:Ser(G).n <=' SUM(G) & Ser(H).n <=' SUM(H) by SUPINF_2:def 23 ; 0. <=' Ser(G).n & 0. <=' Ser(H).n by A2,SUPINF_2:59; then Ser(G).n + Ser(H).n <=' SUM(G) + SUM(H) by A12,MEASURE1:4; hence thesis by A9,A11; end; then sup(rng Ser(F)) <=' SUM(G) + SUM(H) by SUPINF_1:def 16; hence thesis by SUPINF_2:def 23; end; canceled; theorem Th6: for F,G being Function of NAT,ExtREAL holds (F is nonnegative & for n being Nat holds F.n <=' G.n) implies for n being Nat holds (Ser(F)).n <=' SUM(G) proof let F,G be Function of NAT,ExtREAL; assume that A1:F is nonnegative and A2: for n being Nat holds F.n <=' G.n; let n be Nat; A3:SUM(G) = sup(rng Ser(G)) by SUPINF_2:def 23; set y = Ser(G).n; dom Ser(G) = NAT & rng Ser(G) c= ExtREAL by FUNCT_2:def 1; then y in rng Ser(G) & Ser(F).n <=' y by A1,A2,FUNCT_1:def 5,SUPINF_2:61; hence thesis by A3,SUPINF_1:97; end; theorem Th7: for F being Function of NAT,ExtREAL holds F is nonnegative implies for n being Nat holds (Ser(F)).n <=' SUM(F) proof let F be Function of NAT,ExtREAL; for n being Nat holds F.n <=' F.n; hence thesis by Th6; end; definition let S be non empty Subset of NAT; let H be Function of S,NAT; let n be Element of S; redefine func H.n -> Nat; correctness proof H.n is Nat; hence thesis; end; end; definition let S be non empty set; let H be Function of S,ExtREAL; func On H -> Function of NAT,ExtREAL means :Def1:for n being Element of NAT holds (n in S implies it.n = H.n) & (not n in S implies it.n = 0.); existence proof defpred P[Element of NAT,Element of ExtREAL] means ($1 in S implies $2 = H.$1) & (not $1 in S implies $2 = 0.); A1:for n being Element of NAT holds ex y being Element of ExtREAL st P[n,y] proof let n be Element of NAT; per cases; suppose n in S; then reconsider n as Element of S; take H.n; thus thesis; suppose A2:not n in S; take 0.; thus thesis by A2; end; consider GG being Function of NAT,ExtREAL such that A3:for n being Element of NAT holds P[n,GG.n] from FuncExD(A1); take GG; thus thesis by A3; end; uniqueness proof let G1,G2 be Function of NAT,ExtREAL such that A4:for n being Element of NAT holds ((n in S implies G1.n = H.n) & ((not n in S) implies G1.n = 0.)) and A5:for n being Element of NAT holds ((n in S implies G2.n = H.n) & ((not n in S) implies G2.n = 0.)); for n being set st n in NAT holds G1.n = G2.n proof let n be set; assume n in NAT; then reconsider n as Element of NAT; per cases; suppose A6:n in S; then G1.n = H.n by A4; hence thesis by A5,A6; suppose A7:not n in S; then G1.n = 0. by A4; hence thesis by A5,A7; end; hence thesis by FUNCT_2:18; end; end; theorem Th8: for X being non empty set for G being Function of X,ExtREAL st G is nonnegative holds On G is nonnegative proof let X be non empty set; let G be Function of X,ExtREAL; assume A1:G is nonnegative; for n being Nat holds 0. <=' (On G).n proof let n be Nat; per cases; suppose A2:n in X; then (On G).n = G.n by Def1; hence thesis by A1,A2,SUPINF_2:58; suppose not n in X; hence thesis by Def1; end; hence thesis by SUPINF_2:58; end; theorem Th9: for F being Function of NAT,ExtREAL st F is nonnegative holds for n,k being Nat st n <= k holds Ser(F).n <=' Ser(F).k proof let F be Function of NAT,ExtREAL; assume A1:F is nonnegative; let n,k be Nat; assume n <= k; then consider s being Nat such that A2:k = n + s by NAT_1:28; defpred P[Nat] means Ser(F).n <=' Ser(F).(n+$1); A3: P[0]; A4: for k being Nat st P[k] holds P[k+1] proof let k be Nat; assume A5:Ser(F).n <=' Ser(F).(n+k); A6:Ser(F).(n+(k+1)) = Ser(F).((n+k)+1) by XCMPLX_1:1; Ser(F).(n+k) <=' Ser(F).((n+k)+1) by A1,SUPINF_2:59; hence thesis by A5,A6,SUPINF_1:29; end; for s being Nat holds P[s] from Ind(A3,A4); hence thesis by A2; end; theorem Th10: for k being Nat holds for F being Function of NAT,ExtREAL holds ((for n being Nat st n <> k holds F.n = 0.) implies ((for n being Nat st n < k holds Ser(F).n = 0.) & (for n being Nat st k <= n holds Ser(F).n = F.k))) proof let k be Nat; let F be Function of NAT,ExtREAL; assume A1:for n being Nat st n <> k holds F.n = 0.; defpred P[Nat] means $1 < k implies Ser(F).$1 = 0.; A2: P[0] proof assume 0 < k; then F.0 = 0. by A1; hence thesis by SUPINF_2:63; end; A3: for n being Nat st P[n] holds P[n+1] proof let n be Nat; assume A4:n < k implies Ser(F).n = 0.; assume A5:n+1 < k; A6: n <= n+1 by NAT_1:29; A7:F.(n+1) = 0. by A1,A5; Ser(F).(n+1) = Ser(F).n + F.(n+1) by SUPINF_2:63 .= 0. by A4,A5,A6,A7,AXIOMS:22,SUPINF_2:18; hence thesis; end; A8:for n being Nat holds P[n] from Ind(A2,A3); defpred P[Nat] means k <= $1 implies Ser(F).$1 = F.k; A9: P[0] proof assume k <= 0; then k <= 0 & 0 <= k by NAT_1:18; then F.0 = F.k by AXIOMS:21; hence thesis by SUPINF_2:63; end; A10: for n being Nat st P[n] holds P[n+1] proof let n be Nat; assume A11:k <= n implies Ser(F).n = F.k; assume A12:k <= n+1; per cases by A12,NAT_1:26; suppose A13:k <= n; then k <> n+1 by NAT_1:38; then A14:F.(n+1) = 0. by A1; Ser(F).(n+1) = Ser(F).n + F.(n+1) by SUPINF_2:63 .= F.k by A11,A13,A14,SUPINF_2:18; hence thesis; suppose A15:k = n + 1; then n < k by NAT_1:38; then A16:Ser(F).n = 0. by A8; Ser(F).(n+1) = Ser(F).n + F.(n+1) by SUPINF_2:63 .= F.k by A15,A16,SUPINF_2:18; hence thesis; end; for n being Nat holds P[n] from Ind(A9,A10); hence thesis by A8; end; theorem Th11: for G being Function of NAT,ExtREAL st G is nonnegative holds for S being non empty Subset of NAT holds for H being Function of S,NAT st H is one-to-one holds SUM(On(G*H)) <=' SUM(G) proof let G be Function of NAT,ExtREAL; assume A1:G is nonnegative; let S be non empty Subset of NAT; let H be Function of S,NAT; assume A2: H is one-to-one; defpred P[Nat] means ex m being Nat st for F being Function of NAT,ExtREAL st F is nonnegative holds Ser(On(F*H)).$1 <=' Ser(F).m; A3: P[0] proof per cases; suppose A4:0 in S; then reconsider m = H.0 as Nat by FUNCT_2:7; take m; let F be Function of NAT,ExtREAL; assume A5:F is nonnegative; Ser(On(F*H)).0 = (On(F*H)).0 by SUPINF_2:63; then Ser(On(F*H)).0 = (F*H).0 by A4,Def1 .= F.(H.0) by A4,FUNCT_2:21; hence thesis by A5,Th2; suppose A6:not 0 in S; take m = 0; let F be Function of NAT,ExtREAL; assume A7:F is nonnegative; Ser(On(F*H)).0 = (On(F*H)).0 by SUPINF_2:63; then A8:Ser(On(F*H)).0 = 0. by A6,Def1; A9:0. <=' F.0 by A7,SUPINF_2:58; F.0 <=' Ser(F).m by A7,Th2; hence thesis by A8,A9,SUPINF_1:29; end; A10: for k being Nat st P[k] holds P[k+1] proof let k be Nat; given m0 being Nat such that A11:for F being Function of NAT,ExtREAL st F is nonnegative holds Ser(On(F*H)).k <=' Ser(F).m0; per cases; suppose A12:k+1 in S; then reconsider m1 = H.(k+1) as Nat by FUNCT_2:7; set m = m0 + m1; A13: m0 <= m by NAT_1:29; A14: m1 <= m by NAT_1:29; take m; let F be Function of NAT,ExtREAL; assume A15:F is nonnegative; defpred QQ0[Element of NAT,Element of ExtREAL] means (($1 = H.(k+1) implies $2 = F.$1) & ($1 <> H.(k+1) implies $2 = 0.)); A16:for n being Element of NAT holds ex y being Element of ExtREAL st QQ0[n,y] proof let n be Element of NAT; per cases; suppose A17:n = H.(k+1); take F.n; thus thesis by A17; suppose A18:n <> H.(k+1); take 0.; thus thesis by A18; end; consider G0 being Function of NAT,ExtREAL such that A19:for n being Element of NAT holds QQ0[n,G0.n] from FuncExD(A16); for n being Nat holds 0. <=' G0.n proof let n be Nat; per cases; suppose n = H.(k+1); then G0.n = F.n by A19; hence thesis by A15,SUPINF_2:58; suppose not n = H.(k+1);hence thesis by A19; end; then A20:G0 is nonnegative by SUPINF_2:58; defpred QQ1[Element of NAT,Element of ExtREAL] means (($1 <> H.(k+1) implies $2 = F.$1) & ($1 = H.(k+1) implies $2 = 0.)); A21:for n being Element of NAT holds ex y being Element of ExtREAL st QQ1[n,y] proof let n be Element of NAT; per cases; suppose A22:n <> H.(k+1); take F.n; thus thesis by A22; suppose A23:n = H.(k+1); take 0.; thus thesis by A23; end; consider G1 being Function of NAT,ExtREAL such that A24:for n being Element of NAT holds QQ1[n,G1.n] from FuncExD(A21); for n being Nat holds 0. <=' G1.n proof let n be Nat; per cases; suppose n <> H.(k+1); then G1.n = F.n by A24; hence thesis by A15,SUPINF_2:58; suppose n = H.(k+1);hence thesis by A24; end; then A25:G1 is nonnegative by SUPINF_2:58; reconsider GG0 = On(G0*H) as Function of NAT,ExtREAL; G0*H is nonnegative by A20,MEASURE1:54; then A26:GG0 is nonnegative by Th8; reconsider n = k+1 as Element of S by A12; A27: GG0.n = (G0*H).n by Def1 .= G0.(H.n) by FUNCT_2:21 .= F.(H.n) by A19; A28:for n being Element of NAT holds n <> k+1 implies GG0.n = 0. proof let n be Element of NAT; assume A29:n <> k+1; per cases; suppose A30:n in S; then A31:GG0.n = (G0*H).n by Def1 .= G0.(H.n) by A30,FUNCT_2:21; reconsider n as Element of S by A30; not H.n = H.(k+1) by A2,A12,A29,FUNCT_2:25; hence thesis by A19,A31; suppose not n in S; hence thesis by Def1; end; set GG1 = On(G1*H); G1*H is nonnegative by A25,MEASURE1:54; then A32:GG1 is nonnegative by Th8; A33: GG1.(k+1) = (G1*H).n by Def1 .= G1.(H.n) by FUNCT_2:21 .= 0. by A24; A34:for n being Element of NAT holds n <> k+1 & n in S implies GG1.n = F.(H.n) proof let n be Element of NAT; assume A35:n <> k+1 & n in S; then A36:GG1.n = (G1*H).n by Def1 .= G1.(H.n) by A35,FUNCT_2:21; reconsider n as Element of S by A35; not H.n = H.(k+1) by A2,A12,A35,FUNCT_2:25; hence thesis by A24,A36; end; A37:for n being Nat holds On(F*H).n = GG0.n + GG1.n proof let n be Nat; per cases; suppose A38:n = k+1; then On(F*H).n = (F*H).n by A12,Def1 .= F.(H.n) by A12,A38,FUNCT_2:21 .= GG0.n + GG1.n by A27,A33,A38,SUPINF_2:18; hence thesis; suppose A39:n <> k+1; now per cases; suppose A40:n in S; A41:GG0.n = 0. by A28,A39; A42:GG1.n = F.(H.n) by A34,A39,A40; On(F*H).n = (F*H).n by A40,Def1 .= F.(H.n) by A40,FUNCT_2:21 .= GG0.n + GG1.n by A41,A42,SUPINF_2:18; hence thesis; suppose A43:not n in S; A44:GG0.n = 0. by A28,A39; A45:GG1.n = 0. by A43,Def1; On(F*H).n = 0. by A43,Def1 .= GG0.n + GG1.n by A44,A45,SUPINF_2:18; hence thesis; end; hence thesis; end; A46:(Ser GG0).(k+1) = F.(H.(k+1)) by A27,A28,Th10; A47:(Ser G0).m = G0.(H.(k+1)) by A14,A19,Th10; set v = H.n; A48: G0.v = F.v by A19; A49: (Ser GG1).(k+1) = (Ser GG1).k + GG1.(k+1) by SUPINF_2:63 .= (Ser On(G1*H)).k by A33,SUPINF_2:18; A50:(Ser On(G1*H)).k <=' Ser(G1).m0 by A11,A25; Ser(G1).m0 <=' Ser(G1).m by A13,A25,Th9; then A51:(Ser GG1).(k+1) <=' (Ser G1).m by A49,A50,SUPINF_1:29 ; A52: 0. <=' (Ser GG0).(k+1) & 0. <=' (Ser GG1).(k+1) by A26,A32,SUPINF_2:59; for m being Nat holds F.m = G0.m + G1.m proof let m be Nat; per cases; suppose A53:m = H.(k+1); then A54:G0.m = F.m by A19; G1.m = 0.by A24,A53; hence thesis by A54,SUPINF_2:18; suppose A55:m <> H.(k+1); then A56:G0.m = 0. by A19; G1.m = F.m by A24,A55; hence thesis by A56,SUPINF_2:18; end; then (Ser On(F*H)).(k+1) = (Ser GG0).(k+1) + (Ser GG1).(k+1) & (Ser F).m = (Ser G0).m + (Ser G1).m by A20,A25,A26,A32,A37,Th3; hence thesis by A46,A47,A48,A51,A52,MEASURE1:4; suppose A57:not k+1 in S; take m0; let F be Function of NAT,ExtREAL; assume A58:F is nonnegative; A59:On(F*H).(k+1) = 0. by A57,Def1; Ser(On(F*H)).(k+1) = Ser(On(F*H)).k + (On(F*H)).(k+1) by SUPINF_2: 63 .= Ser(On(F*H)).k by A59,SUPINF_2:18; hence thesis by A11,A58; end; A60:for k being Nat holds P[k] from Ind(A3,A10); for x being R_eal st x in rng Ser(On(G*H)) holds (ex y being R_eal st y in rng Ser(G) & x <=' y) proof let x be R_eal; assume A61:x in rng Ser(On(G*H)); ex y being R_eal st y in rng Ser(G) & x <=' y proof consider n being set such that A62:n in dom Ser(On(G*H)) & x = Ser(On(G*H)).n by A61,FUNCT_1:def 5; reconsider n as Nat by A62,FUNCT_2:def 1; consider m being Nat such that A63:for F being Function of NAT,ExtREAL st F is nonnegative holds Ser(On(F*H)).n <=' Ser(F).m by A60; take Ser(G).m; dom Ser(G) = NAT & m in NAT by FUNCT_2:def 1; hence thesis by A1,A62,A63,FUNCT_1:def 5; end; hence thesis; end; then A64:sup(rng Ser(On(G*H))) <=' sup(rng Ser(G)) by SUPINF_1:99; SUM(G) = sup(rng Ser(G)) by SUPINF_2:def 23; hence thesis by A64,SUPINF_2:def 23; end; theorem Th12: for F,G being Function of NAT,ExtREAL st F is nonnegative & G is nonnegative holds for S being non empty Subset of NAT holds for H being Function of S,NAT st H is one-to-one holds (for k being Nat holds ((k in S implies F.k = (G*H).k) & ((not k in S) implies F.k = 0.))) implies SUM(F) <=' SUM(G) proof let F,G be Function of NAT,ExtREAL; assume A1:F is nonnegative & G is nonnegative; let S be non empty Subset of NAT; let H be Function of S,NAT; assume A2:H is one-to-one; assume for k being Nat holds ((k in S implies F.k = (G*H).k) & ((not k in S) implies F.k = 0.)); then F = On(G*H) by Def1; hence thesis by A1,A2,Th11; end; :: :: Outside Lebesque measure :: Lm1: REAL c= REAL; then consider G0 being Function of NAT, bool REAL such that Lm2: rng G0 = {REAL} by MEASURE1:34; REAL in {REAL} by TARSKI:def 1; then Lm3: REAL c= union rng G0 by Lm2,ZFMISC_1:92; Lm4: for n being Nat holds G0.n is Interval proof let n be Nat; G0.n in {REAL} by Lm2,FUNCT_2:6; hence thesis by MEASURE6:35,TARSKI:def 1; end; definition let A be Subset of REAL; mode Interval_Covering of A -> Function of NAT, bool REAL means :Def2:A c= union(rng it) & for n being Nat holds it.n is Interval; existence proof take G0; thus thesis by Lm3,Lm4,XBOOLE_1:1; end; end; definition let A be Subset of REAL; let F be Interval_Covering of A; let n be Nat; redefine func F.n ->Interval; correctness by Def2; end; definition let F be Function of NAT,bool REAL; mode Interval_Covering of F -> Function of NAT,Funcs(NAT,bool REAL) means :Def3:for n being Nat holds it.n is Interval_Covering of F.n; existence proof A1:for n being Nat holds G0 is Interval_Covering of F.n proof let n be Nat; F.n c= union rng G0 by Lm3,XBOOLE_1:1; hence thesis by Def2,Lm4; end; reconsider G = G0 as Element of Funcs(NAT,bool REAL) by FUNCT_2:11; deffunc F(Element of NAT) = G; consider H being Function of NAT,Funcs(NAT,bool REAL) such that A2:for n being Element of NAT holds H.n = F(n) from LambdaD; A3:for n being Nat holds H.n is Interval_Covering of F.n proof let n be Nat; H.n = G by A2; hence thesis by A1; end; take H; thus thesis by A3; end; end; definition let A be Subset of REAL; let F be Interval_Covering of A; deffunc F(Nat) = vol(F.$1); func F vol -> Function of NAT,ExtREAL means :Def4:for n being Nat holds it.n = vol(F.n); existence proof thus ex G being Function of NAT,ExtREAL st for n being Nat holds G.n = F(n) from LambdaD; end; uniqueness proof thus for G1,G2 being Function of NAT,ExtREAL st (for n being Nat holds G1.n = F(n)) & (for n being Nat holds G2.n = F(n)) holds G1=G2 from FuncDefUniq; end; end; theorem Th13: for A being Subset of REAL holds for F being Interval_Covering of A holds (F vol) is nonnegative proof let A be Subset of REAL; let F be Interval_Covering of A; (F vol) is nonnegative proof for n being Nat holds 0. <=' (F vol).n proof let n be Nat; (F vol).n = vol(F.n) by Def4; hence thesis by MEASURE5:63; end; hence thesis by SUPINF_2:58; end; hence thesis; end; definition let F be Function of NAT, bool REAL; let H be Interval_Covering of F; let n be Nat; redefine func H.n -> Interval_Covering of F.n; correctness by Def3; end; definition let F be Function of NAT, bool REAL; let G be Interval_Covering of F; func G vol -> Function of NAT,Funcs(NAT,ExtREAL) means for n being Nat holds it.n = (G.n) vol; existence proof defpred P[Nat,Element of Funcs(NAT,ExtREAL)] means $2 = (G.$1) vol; A1:for n being Element of NAT holds ex y being Element of Funcs(NAT,ExtREAL) st P[n,y] proof let n be Element of NAT; (G.n) vol is Element of Funcs(NAT,ExtREAL) by FUNCT_2:11; hence thesis; end; ex G0 being Function of NAT,Funcs(NAT,ExtREAL) st for n being Element of NAT holds P[n,G0.n] from FuncExD(A1); hence thesis; end; uniqueness proof deffunc F(Nat) = (G.$1) vol; thus for F1,F2 be Function of NAT,Funcs(NAT,ExtREAL) st (for n being Nat holds F1.n = F(n)) & (for n being Nat holds F2.n = F(n)) holds F1 = F2 from FuncDefUniq; end; end; definition let A be Subset of REAL; let F be Interval_Covering of A; func vol(F) -> R_eal equals :Def6: SUM(F vol); correctness; end; definition let F be Function of NAT,(bool REAL); let G be Interval_Covering of F; func vol(G) -> Function of NAT,ExtREAL means :Def7:for n being Nat holds it.n = vol(G.n); existence proof defpred P[Element of NAT,Element of ExtREAL] means $2 = vol(G.$1); A1:for n being Element of NAT holds ex y being Element of ExtREAL st P[n,y]; consider G0 being Function of NAT,ExtREAL such that A2:for n being Element of NAT holds P[n,G0.n] from FuncExD(A1); take G0; thus thesis by A2; end; uniqueness proof deffunc F(Nat) = vol(G.$1); thus for F1,F2 being Function of NAT,ExtREAL st (for n being Nat holds F1.n = F(n)) & (for n being Nat holds F2.n = F(n)) holds F1 = F2 from FuncDefUniq; end; end; theorem Th14: for F being Function of NAT,(bool REAL) holds for G being Interval_Covering of F holds for n being Nat holds 0. <=' (vol(G)).n proof let F be Function of NAT, bool REAL; let G be Interval_Covering of F; let n be Nat; A1:(vol(G)).n = vol(G.n) by Def7; A2:vol(G.n) = SUM((G.n) vol) by Def6; for k being Nat holds 0. <=' ((G.n) vol).k proof let k be Nat; 0. <=' vol((G.n).k) by MEASURE5:63; hence thesis by Def4; end; then ((G.n) vol) is nonnegative by SUPINF_2:58; hence thesis by A1,A2,MEASURE6:2; end; definition let A be Subset of REAL; defpred P[set] means ex F being Interval_Covering of A st $1 = vol(F); func Svc(A) -> Subset of ExtREAL means :Def8:for x being R_eal holds x in it iff ex F being Interval_Covering of A st x = vol(F); existence proof consider D being set such that A1: for x being set holds x in D iff x in ExtREAL & P[x] from Separation; for z being set holds z in D implies z in ExtREAL by A1; then reconsider D as Subset of ExtREAL by TARSKI:def 3; take D; thus thesis by A1; end; uniqueness proof thus for D1,D2 being Subset of ExtREAL st (for x being R_eal holds x in D1 iff P[x]) & (for x being R_eal holds x in D2 iff P[x]) holds D1 = D2 from Subset_Eq; end; end; definition let A be Subset of REAL; cluster Svc(A) -> non empty; coherence proof defpred P[set] means ex F being Interval_Covering of A st $1 = vol(F); consider D being set such that A1:for x being set holds x in D iff x in ExtREAL & P[x] from Separation; consider F0 being Function of NAT, bool REAL such that A2: rng F0 = {REAL,{}} & F0.0 = REAL & for n being Nat st 0 < n holds F0.n = {} by Lm1,MEASURE1:40; A3: union{REAL,{}} = REAL \/ {} by ZFMISC_1:93; for n being Nat holds F0.n is Interval proof let n be Nat; n = 0 or 0 < n by NAT_1:19; hence thesis by A2,MEASURE6:35; end; then reconsider F0 as Interval_Covering of A by A2,A3,Def2; vol F0 in D by A1; hence thesis by Def8; end; end; definition let A be Element of bool REAL; func COMPLEX(A) -> Element of ExtREAL equals :Def9: inf(Svc(A)); correctness; end; definition func OS_Meas -> Function of bool REAL,ExtREAL means :Def10:for A being Subset of REAL holds it.A = inf(Svc(A)); existence proof deffunc F(Subset of REAL) = COMPLEX($1); consider G being Function of bool REAL,ExtREAL such that A1:for A being Element of bool REAL holds G.A = F(A) from LambdaD; A2:for A being Subset of REAL holds G.A = inf(Svc(A)) proof let A be Subset of REAL; G.A = COMPLEX(A) by A1; hence thesis by Def9; end; take G; thus thesis by A2; end; uniqueness proof deffunc F(Subset of REAL) = inf(Svc($1)); thus for F1,F2 being Function of bool REAL,ExtREAL st (for A being Subset of REAL holds F1.A = F(A)) & (for A being Subset of REAL holds F2.A = F(A)) holds F1 = F2 from FuncDefUniq; end; end; definition let H be Function of NAT,[:NAT,NAT:]; redefine func pr1(H) -> Function of NAT,NAT means for n being Element of NAT holds ex s being Element of NAT st H.n = [it.n,s]; coherence proof A1: dom pr1 H = dom H by DTCONSTR:def 2; then A2: dom pr1 H = NAT by FUNCT_2:def 1; rng pr1 H c= NAT proof let x be set; assume x in rng pr1 H; then consider y being set such that A3: y in dom pr1 H and A4: x = (pr1 H).y by FUNCT_1:def 5; A5: x = (H.y)`1 by A1,A3,A4,DTCONSTR:def 2; H.y in [:NAT,NAT:] by A2,A3,FUNCT_2:7; hence x in NAT by A5,MCART_1:10; end; hence pr1 H is Function of NAT,NAT by A2,FUNCT_2:4; end; compatibility proof let IT be Function of NAT,NAT; A6: dom pr1 H = dom H by DTCONSTR:def 2; then A7: dom pr1 H = NAT by FUNCT_2:def 1; hereby assume A8: IT = pr1 H; let n be Element of NAT; A9: IT.n = (H.n)`1 by A6,A7,A8,DTCONSTR:def 2; reconsider s = (H.n)`2 as Element of NAT by MCART_1:10; take s; thus H.n = [IT.n,s] by A9,MCART_1:24; end; assume A10: for n being Element of NAT holds ex s being Element of NAT st H.n = [IT.n,s]; A11: for x being set st x in dom H holds IT.x = (H.x)`1 proof let x be set; assume x in dom H; then reconsider n = x as Nat by FUNCT_2:def 1; ex s being Element of NAT st H.n = [IT.n,s] by A10; hence IT.x = (H.x)`1 by MCART_1:7; end; dom IT = dom H by A6,A7,FUNCT_2:def 1; hence IT = pr1 H by A11,DTCONSTR:def 2; end; end; definition let H be Function of NAT,[:NAT,NAT:]; redefine func pr2(H) -> Function of NAT,NAT means :Def12:for n being Element of NAT holds H.n = [pr1(H).n,it.n]; coherence proof A1: dom pr2 H = dom H by DTCONSTR:def 3; then A2: dom pr2 H = NAT by FUNCT_2:def 1; rng pr2 H c= NAT proof let x be set; assume x in rng pr2 H; then consider y being set such that A3: y in dom pr2 H and A4: x = (pr2 H).y by FUNCT_1:def 5; A5: x = (H.y)`2 by A1,A3,A4,DTCONSTR:def 3; H.y in [:NAT,NAT:] by A2,A3,FUNCT_2:7; hence x in NAT by A5,MCART_1:10; end; hence pr2 H is Function of NAT,NAT by A2,FUNCT_2:4; end; compatibility proof let IT be Function of NAT,NAT; A6: dom pr2 H = dom H by DTCONSTR:def 3; then A7: dom pr2 H = NAT by FUNCT_2:def 1; hereby assume A8: IT = pr2 H; let n be Element of NAT; A9: IT.n = (H.n)`2 by A6,A7,A8,DTCONSTR:def 3; (pr1 H).n = (H.n)`1 by A6,A7,DTCONSTR:def 2; hence H.n = [(pr1 H).n,IT.n] by A9,MCART_1:24; end; assume A10: for n being Element of NAT holds H.n = [(pr1 H).n,IT.n]; A11: for x being set st x in dom H holds IT.x = (H.x)`2 proof let x be set; assume x in dom H; then reconsider n = x as Nat by FUNCT_2:def 1; H.n = [(pr1 H).n,IT.n] by A10; hence IT.x = (H.x)`2 by MCART_1:7; end; dom IT = dom H by A6,A7,FUNCT_2:def 1; hence IT = pr2 H by A11,DTCONSTR:def 3; end; end; definition let F be Function of NAT,bool REAL; let G be Interval_Covering of F; let H be Function of NAT,[:NAT,NAT:] such that A1: rng H = [:NAT,NAT:]; func On(G,H) -> Interval_Covering of union rng F means :Def13:for n being Element of NAT holds it.n = (G.(pr1(H).n)).(pr2(H).n); existence proof defpred P[Element of NAT,Element of bool REAL] means $2 = (G.(pr1(H).$1)).(pr2(H).$1); A2:for n being Element of NAT holds ex y being Element of bool REAL st P[n,y]; consider GG being Function of NAT,bool REAL such that A3:for n being Element of NAT holds P[n,GG.n] from FuncExD(A2); GG is Interval_Covering of union rng F proof A4:union rng F c= union(rng GG) proof let x be set; assume x in union rng F; then consider A being set such that A5:x in A & A in rng F by TARSKI:def 4; consider n1 being set such that A6:n1 in dom F & A = F.n1 by A5,FUNCT_1:def 5; reconsider n1 as Nat by A6,FUNCT_2:def 1; F.n1 c= union rng(G.n1) by Def2; then consider AA being set such that A7:x in AA & AA in rng(G.n1) by A5,A6,TARSKI:def 4; consider n2 being set such that A8:n2 in dom(G.n1) & AA = (G.n1).n2 by A7,FUNCT_1:def 5; reconsider n2 as Nat by A8,FUNCT_2:def 1; [n1,n2] in rng H by A1,ZFMISC_1:106; then consider n being set such that A9:n in dom(H) & [n1,n2] = H.n by FUNCT_1:def 5; reconsider n as Nat by A9,FUNCT_2:def 1; [pr1(H).n,pr2(H).n] = [n1,n2] by A9,Def12; then pr1(H).n = n1 & pr2(H).n = n2 by ZFMISC_1:33; then x in GG.n & GG.n in rng GG by A3,A7,A8,FUNCT_2:6; hence thesis by TARSKI:def 4; end; for n being Nat holds GG.n is Interval proof let n be Nat; GG.n = (G.(pr1(H).n)).(pr2(H).n) by A3; hence thesis; end; hence thesis by A4,Def2; end; then reconsider GG as Interval_Covering of union rng F; take GG; thus thesis by A3; end; uniqueness proof let G1,G2 be Interval_Covering of union rng F such that A10:for n being Element of NAT holds G1.n = (G.(pr1(H).n)).(pr2(H).n) and A11:for n being Element of NAT holds G2.n = (G.(pr1(H).n)).(pr2(H).n); for n being set st n in NAT holds G1.n = G2.n proof let n be set; assume n in NAT; then reconsider n as Element of NAT; G1.n = (G.(pr1(H).n)).(pr2(H).n) by A10; hence thesis by A11; end; hence thesis by FUNCT_2:18; end; end; theorem Th15: for H being Function of NAT,[:NAT,NAT:] st H is one-to-one & rng H = [:NAT,NAT:] holds for k being Nat holds ex m being Nat st for F being Function of NAT,bool REAL holds for G being Interval_Covering of F holds Ser((On(G,H)) vol).k <=' Ser(vol(G)).m proof let H be Function of NAT,[:NAT,NAT:]; assume that A1:H is one-to-one and A2: rng H = [:NAT,NAT:]; deffunc F(Nat) = {}; consider D being Function of NAT,bool REAL such that A3: for n being Element of NAT holds D.n = F(n) from LambdaD; reconsider y = D as Element of Funcs(NAT,bool REAL) by FUNCT_2:11; defpred P[Nat] means ex m being Nat st for F being Function of NAT,bool REAL holds for G being Interval_Covering of F holds Ser((On(G,H)) vol).($1) <=' Ser(vol(G)).m; A4: P[0] proof take m = pr1(H).0; let F be Function of NAT,bool REAL; let G be Interval_Covering of F; reconsider GG = On(G,H) as Interval_Covering of union rng F; A5:Ser(GG vol).0 = (GG vol).0 by SUPINF_2:63; (GG vol).0 = vol(GG.0) & ((G.(pr1(H).0)) vol).(pr2(H).0) = vol((G.(pr1(H).0)).(pr2(H).0)) by Def4; then A6:(GG vol).0 <=' ((G.(pr1(H).0)) vol).(pr2(H).0) by A2,Def13; ((G.(pr1(H).0))) vol is nonnegative by Th13; then (GG vol).0 <=' SUM((G.(pr1(H).0)) vol) by A6,MEASURE6:3; then (GG vol).0 <=' vol(G.(pr1(H).0)) by Def6; then A7:(GG vol).0 <=' (vol(G)).(pr1(H).0) by Def7; for n being Nat holds 0. <=' (vol(G)).n by Th14; then vol(G) is nonnegative by SUPINF_2:58; then (vol(G)).m <=' Ser(vol(G)).m by Th2; hence thesis by A5,A7,SUPINF_1:29; end; A8: for k being Nat st P[k] holds P[k+1] proof let k be Nat; given m0 being Nat such that A9: for F being Function of NAT,bool REAL holds for G being Interval_Covering of F holds Ser((On(G,H)) vol).k <=' Ser(vol(G)).m0; take m = m0 + pr1(H).(k+1); let F be Function of NAT,bool REAL; let G be Interval_Covering of F; defpred QQ0[Element of NAT,Element of Funcs(NAT,bool REAL)] means (($1 = pr1(H).(k+1) implies for m being Nat holds $2.m = (G.$1).m) & ($1 <> pr1(H).(k+1) implies for m being Nat holds $2.m = {})); A10:for n being Element of NAT holds ex y being Element of Funcs(NAT,bool REAL) st QQ0[n,y] proof let n be Element of NAT; per cases; suppose A11:n = pr1(H).(k+1); reconsider y = G.n as Element of Funcs(NAT,bool REAL) by FUNCT_2:11; take y; thus thesis by A11; suppose A12:n <> pr1(H).(k+1); take y; thus thesis by A3,A12; end; consider G0 being Function of NAT,Funcs(NAT,bool REAL) such that A13:for n being Element of NAT holds QQ0[n,G0.n] from FuncExD(A10); defpred QQ1[Element of NAT,Element of Funcs(NAT,bool REAL)] means (($1 <> pr1(H).(k+1) implies for m being Nat holds $2.m = (G.$1).m) & ($1 = pr1(H).(k+1) implies for m being Nat holds $2.m = {})); A14:for n being Element of NAT holds ex y being Element of Funcs(NAT,bool REAL) st QQ1[n,y] proof let n be Element of NAT; per cases; suppose A15:n <> pr1(H).(k+1); reconsider y = G.n as Element of Funcs(NAT,bool REAL) by FUNCT_2:11; take y; thus thesis by A15; suppose A16:n = pr1(H).(k+1); take y; thus thesis by A3,A16; end; consider G1 being Function of NAT,Funcs(NAT,bool REAL) such that A17:for n being Element of NAT holds QQ1[n,G1.n] from FuncExD(A14); for n being Nat holds G0.n is Interval_Covering of D.n proof let n be Nat; consider f0 being Function such that A18:G0.n = f0 & dom f0 = NAT & rng f0 c= bool REAL by FUNCT_2:def 2; reconsider f0 as Function of NAT,bool REAL by A18,FUNCT_2:4; D.n = {} by A3; then A19:D.n c= union(rng f0) by XBOOLE_1:2; for s being Nat holds f0.s is Interval proof let s be Element of NAT; per cases; suppose n = pr1(H).(k+1); then f0.s = (G.n).s by A13,A18; hence thesis; suppose n <> pr1(H).(k+1); hence thesis by A13,A18; end; then reconsider f0 as Interval_Covering of D.n by A19,Def2; G0.n = f0 by A18; hence thesis; end; then reconsider G0 as Interval_Covering of D by Def3; set GG0 = On(G0,H); for n being Nat holds G1.n is Interval_Covering of D.n proof let n be Nat; consider f0 being Function such that A20:G1.n = f0 & dom f0 = NAT & rng f0 c= bool REAL by FUNCT_2:def 2; reconsider f0 as Function of NAT,bool REAL by A20,FUNCT_2:4; D.n = {} by A3; then A21:D.n c= union(rng f0) by XBOOLE_1:2; for s being Nat holds f0.s is Interval proof let s be Element of NAT; per cases; suppose n <> pr1(H).(k+1); then f0.s = (G.n).s by A17,A20; hence thesis; suppose n = pr1(H).(k+1); hence thesis by A17,A20; end; then reconsider f0 as Interval_Covering of D.n by A21,Def2; G1.n = f0 by A20; hence thesis; end; then reconsider G1 as Interval_Covering of D by Def3; set GG1 = On(G1,H); A22:for n being Nat holds (vol(G)).n = (vol(G0)).n + (vol(G1)).n proof let n be Nat; A23:(vol(G)).n = vol(G.n) & (vol(G0)).n = vol(G0.n) & (vol(G1)).n = vol(G1.n) by Def7; vol(G.n) = vol(G0.n) + vol(G1.n) proof A24:(G.n) vol is nonnegative & (G0.n) vol is nonnegative by Th13; per cases; suppose A25:n = pr1(H).(k+1); A26:SUM((G.n) vol) = SUM((G0.n) vol) + SUM((G1.n) vol) proof for s being Nat holds ((G1.n) vol).s = 0. proof let s be Nat; vol((G1.n).s) = 0. by A17,A25,MEASURE5:60; hence thesis by Def4; end; then A27:SUM((G1.n) vol) = 0. by Th1; for s being Nat holds ((G0.n) vol).s <=' ((G.n) vol).s proof let s be Nat; ((G0.n) vol).s = vol((G0.n).s) by Def4 .= vol((G.n).s) by A13,A25 .= ((G.n) vol).s by Def4; hence thesis; end; then A28:SUM((G0.n) vol) <=' SUM((G.n) vol) by A24,SUPINF_2:62; for s being Nat holds ((G.n) vol).s <=' ((G0.n) vol).s proof let s be Nat; ((G0.n) vol).s = vol((G0.n).s) by Def4 .= vol((G.n).s) by A13,A25 .= ((G.n) vol).s by Def4; hence thesis; end; then SUM((G.n) vol) <=' SUM((G0.n) vol) by A24,SUPINF_2:62; then SUM((G.n) vol) = SUM((G0.n) vol) by A28,SUPINF_1:22; hence thesis by A27,SUPINF_2:18; end; vol(G0.n) = SUM((G0.n) vol) & vol(G1.n) = SUM((G1.n) vol) by Def6; hence thesis by A26,Def6; suppose A29:n <> pr1(H).(k+1); A30:for s being Nat holds ((G1.n) vol).s = ((G.n) vol).s proof let s be Nat; ((G1.n) vol).s = vol((G1.n).s) & ((G.n) vol).s = vol((G.n).s) by Def4; hence thesis by A17,A29; end; A31:for s being Nat holds ((G0.n) vol).s = 0. proof let s be Nat; vol((G0.n).s) = 0. by A13,A29,MEASURE5:60; hence thesis by Def4; end; A32:SUM((G.n) vol) = SUM((G0.n) vol) + SUM((G1.n) vol) proof A33:(G.n) vol is nonnegative & (G1.n) vol is nonnegative by Th13; A34:SUM((G0.n) vol) = 0. by A31,Th1; for s being Nat holds ((G1.n) vol).s <=' ((G.n) vol).s by A30; then A35:SUM((G1.n) vol) <=' SUM((G.n) vol) by A33,SUPINF_2:62; for s being Nat holds ((G.n) vol).s <=' ((G1.n) vol).s by A30; then SUM((G.n) vol) <=' SUM((G1.n) vol) by A24,SUPINF_2:62; then SUM((G.n) vol) = SUM((G1.n) vol) by A35,SUPINF_1:22; hence thesis by A34,SUPINF_2:18; end; vol(G0.n) = SUM((G0.n) vol) & vol(G1.n) = SUM((G1.n) vol) by Def6; hence thesis by A32,Def6; end; hence thesis by A23; end; A36: GG0 vol is nonnegative by Th13; A37: GG1 vol is nonnegative by Th13; A38:(Ser(GG0 vol)).(k+1) <=' SUM(GG0 vol) by A36,Th7; A39: G0.(pr1(H).(k+1)) vol is nonnegative by Th13; set N0 = {s where s is Nat : pr1(H).(k+1) = pr1(H).s}; A40: N0 c= NAT proof let s1 be set; assume s1 in N0; then ex s being Nat st s = s1 & pr1(H).(k+1) = pr1(H).s; hence thesis; end; k+1 in N0; then reconsider N0 as non empty Subset of NAT by A40; defpred SSS[Element of N0,Element of NAT] means $2 = pr2(H).$1; A41:for s being Element of N0 holds ex y being Element of NAT st SSS[s,y]; consider SOS being Function of N0,NAT such that A42:for s being Element of N0 holds SSS[s,SOS.s] from FuncExD(A41); for s1,s2 being set st s1 in N0 & s2 in N0 & SOS.s1 = SOS.s2 holds s1 = s2 proof let s1,s2 be set; assume A43:s1 in N0 & s2 in N0 & SOS.s1 = SOS.s2; then reconsider s1,s2 as Nat; consider s11 being Nat such that A44:s11 = s1 & pr1(H).(k+1) = pr1(H).s11 by A43; consider s22 being Nat such that A45:s22 = s2 & pr1(H).(k+1) = pr1(H).s22 by A43; A46: SOS.s1 = pr2(H).s1 & SOS.s2 = pr2(H).s2 by A42,A43; H.s1 = [pr1(H).s1,pr2(H).s1] & H.s2 = [pr1(H).s2,pr2(H).s2] by Def12; hence thesis by A1,A43,A44,A45,A46,FUNCT_2:25; end; then A47: SOS is one-to-one by FUNCT_2:25; for s being Nat holds ((s in N0 implies (GG0 vol).s = ((G0.(pr1(H).(k+1)) vol)*SOS).s) & (not s in N0 implies (GG0 vol).s = 0.)) proof let s be Nat; thus s in N0 implies (GG0 vol).s = ((G0.(pr1(H).(k+1)) vol)*SOS).s proof assume A48:s in N0; then consider s1 being Nat such that A49:s1 = s & pr1(H).(k+1) = pr1(H).s1; A50:pr2(H).s =SOS.s by A42,A48; (GG0 vol).s = vol(GG0.s) by Def4 .= vol((G0.(pr1(H).(k+1))).(pr2(H).s)) by A2,A49,Def13 .= (G0.(pr1(H).(k+1)) vol).(SOS.s) by A50,Def4 .= ((G0.(pr1(H).(k+1)) vol)*SOS).s by A48,FUNCT_2:21; hence thesis; end; assume not s in N0; then A51:not pr1(H).(k+1) = pr1(H).s; (GG0 vol).s = vol(GG0.s) by Def4 .= vol((G0.(pr1(H).s)).(pr2(H).s)) by A2,Def13 .= 0. by A13,A51,MEASURE5:60; hence thesis; end; then A52:SUM(GG0 vol) <=' SUM(G0.(pr1(H).(k+1)) vol) by A36,A39,A47,Th12; A53:SUM(G0.(pr1(H).(k+1)) vol) = vol(G0.(pr1(H).(k+1))) by Def6 .= (vol(G0)).(pr1(H).(k+1)) by Def7; for s being Nat holds 0. <=' (vol(G0)).s by Th14; then A54:vol(G0) is nonnegative by SUPINF_2:58; then A55:(vol(G0)).(pr1(H).(k+1)) <=' (Ser(vol(G0))).(pr1(H).(k+1 )) by Th2; (Ser vol(G0)).(pr1(H).(k+1)) <=' (Ser vol(G0)).m by A54,SUPINF_2:60; then A56:SUM(G0.(pr1(H).(k+1)) vol) <=' (Ser vol(G0)).m by A53,A55,SUPINF_1:29; (Ser(GG0 vol)).(k+1) <=' SUM(G0.(pr1(H).(k+1)) vol) by A38,A52,SUPINF_1:29; then A57:(Ser (GG0 vol)).(k+1) <=' (Ser vol(G0)).m by A56, SUPINF_1:29; A58:(Ser(GG1 vol)).k <=' (Ser vol(G1)).m0 by A9; GG1.(k+1) = (G1.(pr1(H).(k+1))).(pr2(H).(k+1)) by A2,Def13 .= {} by A17; then A59: (GG1 vol).(k+1) = 0. by Def4,MEASURE5:60; (Ser (GG1 vol)).(k+1) = (Ser (GG1 vol)).k + (GG1 vol).(k+1) by SUPINF_2:63; then A60: (Ser (GG1 vol)).(k+1) = (Ser (GG1 vol)).k by A59,SUPINF_2:18; for s being Nat holds 0. <=' (vol(G1)).s by Th14; then vol(G1) is nonnegative by SUPINF_2:58; then (Ser vol(G1)).m0 <=' (Ser vol(G1)).m by SUPINF_2:60; then A61:(Ser (GG1 vol)).(k+1) <=' (Ser vol(G1)).m by A58,A60, SUPINF_1:29; GG0 vol is nonnegative & GG1 vol is nonnegative by Th13; then A62: 0. <=' (Ser (GG0 vol)).(k+1) & 0. <=' (Ser (GG1 vol)).(k+1) by SUPINF_2:59; for s being Nat holds 0. <=' (vol(G0)).s by Th14; then A63:vol(G0) is nonnegative by SUPINF_2:58; for s being Nat holds 0. <=' (vol(G1)).s by Th14; then vol(G1) is nonnegative by SUPINF_2:58; then A64: (Ser vol(G)).m = (Ser vol(G0)).m + (Ser vol(G1)).m by A22,A63,Th3; for n being Nat holds ((On(G,H)) vol).n = (GG0 vol).n + (GG1 vol).n proof let n be Nat; A65:((On(G,H)) vol).n = vol((On(G,H)).n) & (GG0 vol).n = vol(GG0.n) & (GG1 vol).n = vol(GG1.n) by Def4; then A66:((On(G,H)) vol).n = vol((G.(pr1(H).n)).(pr2(H).n)) by A2,Def13; per cases; suppose A67:pr1(H).n = pr1(H).(k+1); A68: GG0.n = (G0.(pr1(H).n)).(pr2(H).n) by A2,Def13 .= (G.(pr1(H).n)).(pr2(H).n) by A13,A67; GG1.n = (G1.(pr1(H).n)).(pr2(H).n) by A2,Def13 .= {} by A17,A67; hence thesis by A65,A66,A68,MEASURE5:60,SUPINF_2:18; suppose A69:pr1(H).n <> pr1(H).(k+1); A70: GG1.n = (G1.(pr1(H).n)).(pr2(H).n) by A2,Def13 .= (G.(pr1(H).n)).(pr2(H).n) by A17,A69; GG0.n = (G0.(pr1(H).n)).(pr2(H).n) by A2,Def13 .= {} by A13,A69; hence thesis by A65,A66,A70,MEASURE5:60,SUPINF_2:18; end; then (Ser (On(G,H) vol)).(k+1) = (Ser (GG0 vol)).(k+1) + (Ser (GG1 vol)).(k+1) by A36,A37,Th3; hence thesis by A57,A61,A62,A64,MEASURE1:4; end; thus for k being Nat holds P[k] from Ind(A4,A8); end; theorem Th16: for F being Function of NAT,bool REAL holds for G being Interval_Covering of F holds inf Svc(union rng F) <=' SUM(vol(G)) proof let F be Function of NAT,bool REAL; let G be Interval_Covering of F; consider H being Function of NAT,[:NAT,NAT:] such that A1:H is one-to-one & dom H = NAT & rng H = [:NAT,NAT:] by MEASURE6:1; set GG = On(G,H); set Q = vol(GG); SUM(GG vol) = sup(rng Ser(GG vol)) by SUPINF_2:def 23; then A2:vol(GG) = sup(rng Ser(GG vol)) by Def6; A3:SUM(vol(G)) = sup(rng Ser(vol(G))) by SUPINF_2:def 23; for x being R_eal st x in rng Ser(GG vol) ex y being R_eal st y in rng Ser(vol(G)) & x <=' y proof let x be R_eal; assume x in rng Ser(GG vol); then consider n being set such that A4:n in dom Ser(GG vol) & x = Ser(GG vol).n by FUNCT_1:def 5; reconsider n as Nat by A4,FUNCT_2:def 1; consider m being Nat such that A5:for F being Function of NAT,bool REAL holds for G be Interval_Covering of F holds Ser((On(G,H)) vol).n <=' Ser(vol(G)).m by A1,Th15; take Ser(vol(G)).m; dom Ser(vol(G)) = NAT & m in NAT by FUNCT_2:def 1; hence thesis by A4,A5,FUNCT_1:def 5; end; then A6: vol(GG) <=' SUM(vol(G)) by A2,A3,SUPINF_1:99; Q in Svc(union rng F) by Def8; then inf Svc(union rng F) <=' Q by SUPINF_1:79; hence thesis by A6,SUPINF_1:29; end; theorem Th17: OS_Meas is C_Measure of REAL proof A1:for A being Subset of REAL holds for F being Interval_Covering of A holds F vol is nonnegative proof let A be Subset of REAL; let F be Interval_Covering of A; for n being Nat holds 0. <=' (F vol).n proof let n be Nat; (F vol).n = vol(F.n) by Def4; hence thesis by MEASURE5:63; end; hence thesis by SUPINF_2:58; end; A2: for A being Element of bool REAL holds 0.<=' OS_Meas.A proof let A be Element of bool REAL; A3:OS_Meas.A = inf(Svc(A)) by Def10; 0. is minorant of Svc(A) proof let x be R_eal; assume x in Svc(A); then consider F being Interval_Covering of A such that A4:x = vol(F) by Def8; A5:F vol is nonnegative by A1; A6:SUM(F vol) = sup(rng Ser(F vol)) by SUPINF_2:def 23; set y = Ser(F vol).0; y in rng Ser(F vol) & 0. <=' y by A5,FUNCT_2:6,SUPINF_2:59; then 0. <=' y & y <=' sup(rng Ser(F vol)) by SUPINF_1:76; then 0. <=' SUM(F vol) by A6,SUPINF_1:29; hence thesis by A4,Def6; end; hence thesis by A3,SUPINF_1:def 17; end; hence OS_Meas is nonnegative by MEASURE1:def 4; deffunc F(Nat) = {}; consider G being Function of NAT,bool REAL such that A7:for n being Element of NAT holds G.n = F(n) from LambdaD; A8:{} c= union(rng G) by XBOOLE_1:2; for n being Nat holds G.n is Interval by A7; then reconsider G as Interval_Covering of {} by A8,Def2; A9:G vol is nonnegative by A1; A10: for r being Nat holds 0 <= r implies (G vol).r = 0. proof let n be Nat; vol(G.n) = vol({}) by A7; hence thesis by Def4,MEASURE5:60; end; vol(G) = SUM(G vol) by Def6 .= Ser(G vol).0 by A9,A10,SUPINF_2:67 .= (G vol).0 by SUPINF_2:63 .= 0. by A10; then A11:0. in Svc({}) by Def8; 0. is minorant of Svc {} proof let x be R_eal; assume A12:x in Svc({}); 0. <=' OS_Meas.{} by A2; then 0. <=' inf Svc({}) & inf Svc({}) <=' x by A12,Def10,SUPINF_1: 79; hence thesis by SUPINF_1:29; end; then inf Svc {} = 0. by A11,SUPINF_1:81; hence OS_Meas.{} = 0. by Def10; let A,B be Element of bool REAL; assume A13:A c= B; A14: Svc(B) c= Svc(A) proof let x be set; assume A15:x in Svc(B); then reconsider x as R_eal; consider F being Interval_Covering of B such that A16:x = vol(F) by A15,Def8; A17: B c= union(rng F) & for n being Nat holds F.n is Interval by Def2; then A c= union(rng F) by A13,XBOOLE_1:1; then reconsider G = F as Interval_Covering of A by A17,Def2; x = vol(G) proof A18: for n being Nat holds (G vol).n <=' (F vol).n proof let n be Nat; (G vol).n = vol(G.n) by Def4 .= (F vol).n by Def4; hence thesis; end; G vol is nonnegative by A1; then A19:SUM(G vol) <=' SUM(F vol) by A18,SUPINF_2:62; A20: for n being Nat holds (F vol).n <=' (G vol).n proof let n be Nat; (G vol).n = vol(G.n) by Def4 .= (F vol).n by Def4; hence thesis; end; F vol is nonnegative by A1; then A21: SUM(F vol) <=' SUM(G vol) by A20,SUPINF_2:62; vol(F) = SUM(F vol) & vol(G) = SUM(G vol) by Def6; hence thesis by A16,A19,A21,SUPINF_1:22; end; hence thesis by Def8; end; OS_Meas.A = inf Svc(A) & OS_Meas.B = inf Svc(B) by Def10; hence OS_Meas.A <=' OS_Meas.B by A14,SUPINF_1:94; let F be Function of NAT,bool REAL; per cases; suppose A22:for n being Nat holds Svc(F.n) <> {+infty}; A23:SUM(OS_Meas*F) = sup(rng Ser(OS_Meas*F)) by SUPINF_2:def 23; A24:for n being Nat holds 0. <=' (OS_Meas*F).n proof let n be Nat; (OS_Meas*F).n = OS_Meas.(F.n) by FUNCT_2:21; hence thesis by A2; end; then A25:OS_Meas*F is nonnegative by SUPINF_2:58; inf Svc(union rng F) <=' sup(rng Ser(OS_Meas*F)) proof assume A26:not inf Svc(union rng F) <=' sup(rng Ser(OS_Meas*F)); set y = inf Svc(union rng F), x = sup(rng Ser(OS_Meas*F)); 0. <=' (OS_Meas*F).0 by A24; then A27:0. <=' Ser(OS_Meas*F).0 by SUPINF_2:63; Ser(OS_Meas*F).0 in rng Ser(OS_Meas*F) by FUNCT_2:6; then Ser(OS_Meas*F).0 <=' x by SUPINF_1:76; then 0. <=' x by A27,SUPINF_1:29; then consider eps being R_eal such that A28:0. <' eps & x + eps <' y & eps in REAL by A26,MEASURE6:25; consider E being Function of NAT,ExtREAL such that A29:(for n being Nat holds 0. <' E.n) & SUM(E) <' eps by A28,MEASURE6:31; defpred P[Element of NAT,Element of Funcs(NAT,bool REAL)] means ex F0 being Interval_Covering of F.$1 st ($2 = F0 & (vol(F0) <' inf Svc(F.$1) + E.$1)); A30:for n being Element of NAT holds ex F0 being Element of Funcs(NAT,bool REAL) st P[n,F0] proof let n be Element of NAT; A31: OS_Meas.(F.n) = inf Svc(F.n) & 0. <=' OS_Meas.(F.n) by A2,Def10; Svc(F.n) <> {+infty} by A22; then not Svc(F.n) c= {+infty} by ZFMISC_1:39; then Svc(F.n) \ {+infty} <> {} by XBOOLE_1:37; then consider x being set such that A32:x in Svc(F.n) \ {+infty} by XBOOLE_0:def 1; reconsider x as R_eal by A32; A33: x in Svc(F.n) & not x in {+infty} by A32,XBOOLE_0:def 4; then A34:x in Svc(F.n) & x <> +infty by TARSKI:def 1; A35:inf Svc(F.n) <=' x by A33,SUPINF_1:79; x <=' +infty by SUPINF_1:20; then x <' +infty by A34,SUPINF_1:22; then 0. is Real & 0. <=' inf Svc(F.n) & inf Svc(F.n) <' +infty by A31,A35,SUPINF_1:29,SUPINF_2:def 1; then 0. <' E.n & inf Svc(F.n) is Real by A29,MEASURE6:17; then consider S being R_eal such that A36: S in Svc(F.n) & S <' inf Svc(F.n) + E.n by MEASURE6:32; consider FS being Interval_Covering of F.n such that A37:S = vol(FS) by A36,Def8; reconsider FS as Element of Funcs(NAT,bool REAL) by FUNCT_2:11; take FS; thus thesis by A36,A37; end; consider FF being Function of NAT,Funcs(NAT,bool REAL) such that A38:for n being Element of NAT holds P[n,FF.n] from FuncExD(A30); for n being Nat holds FF.n is Interval_Covering of F.n proof let n be Nat; consider F0 being Interval_Covering of F.n such that A39:F0 = FF.n & vol(F0) <' inf Svc(F.n) + E.n by A38; thus thesis by A39; end; then reconsider FF as Interval_Covering of F by Def3; for n being Nat holds 0. <=' E.n by A29; then A40:E is nonnegative by SUPINF_2:58; defpred P1[Element of NAT,Element of ExtREAL] means $2 = (OS_Meas*F).$1 + E.$1; A41:for n being Element of NAT holds ex y being Element of ExtREAL st P1[n,y]; consider G0 being Function of NAT,ExtREAL such that A42:for n being Element of NAT holds P1[n,G0.n] from FuncExD(A41); A43:SUM(G0) <=' SUM(OS_Meas*F) + SUM(E) by A25,A40,A42,Th4; A44:for n being Nat holds (vol(FF)).n <=' G0.n proof let n be Nat; consider F0 being Interval_Covering of F.n such that A45:F0 = FF.n & vol(F0) <' inf Svc(F.n) + E.n by A38; (OS_Meas*F).n = OS_Meas.(F.n) by FUNCT_2:21; then vol(FF.n) <' (OS_Meas*F).n + E.n by A45,Def10; then (vol(FF)).n <' (OS_Meas*F).n + E.n by Def7; hence thesis by A42; end; for n being Nat holds 0. <=' (vol(FF)).n by Th14; then vol(FF) is nonnegative by SUPINF_2:58; then A46:SUM(vol(FF)) <=' SUM(G0) by A44,SUPINF_2:62; 0. <=' SUM(OS_Meas*F) & 0. <=' SUM(E) by A25,A40,MEASURE6:2; then SUM(OS_Meas*F) + SUM(E) <=' SUM(OS_Meas*F) + eps by A29,MEASURE1:4; then SUM(G0) <=' SUM(OS_Meas*F) + eps by A43,SUPINF_1:29; then A47:SUM (vol(FF)) <=' SUM (OS_Meas*F) + eps by A46,SUPINF_1 :29; y <=' SUM vol(FF) by Th16; hence thesis by A23,A28,A47,SUPINF_1:29; end; hence thesis by A23,Def10; suppose ex n being Nat st Svc(F.n) = {+infty}; then consider n being Nat such that A48:Svc(F.n) = {+infty}; OS_Meas.(F.n) = +infty by A48,Def10,SUPINF_1:90; then A49: (OS_Meas*F).n = +infty by FUNCT_2:21; for n being Nat holds 0. <=' (OS_Meas*F).n proof let n be Nat; (OS_Meas*F).n = OS_Meas.(F.n) by FUNCT_2:21; hence thesis by A2; end; then OS_Meas*F is nonnegative by SUPINF_2:58; then SUM(OS_Meas*F) = +infty by A49,SUPINF_2:64; hence thesis by SUPINF_1:20; end; definition redefine func OS_Meas -> C_Measure of REAL; correctness by Th17; end; definition func Lmi_sigmaFIELD -> sigma_Field_Subset of REAL equals :Def14: sigma_Field(OS_Meas); correctness; end; definition func L_mi -> sigma_Measure of Lmi_sigmaFIELD equals :Def15: sigma_Meas(OS_Meas); correctness by Def14; end; theorem L_mi is_complete Lmi_sigmaFIELD by Def14,Def15,MEASURE4:25; canceled 2; theorem for A being set st A in Lmi_sigmaFIELD holds REAL \ A in Lmi_sigmaFIELD by Def14,MEASURE4:16;