Copyright (c) 2000 Association of Mizar Users
environ vocabulary WAYBEL_9, WAYBEL_0, CANTOR_1, WAYBEL11, BHSP_3, PRELAMB, YELLOW_9, PRE_TOPC, RELAT_2, ORDINAL2, CONNSP_2, REALSET1, SETFAM_1, BOOLE, WAYBEL19, TARSKI, FINSET_1, SUBSET_1, YELLOW_2, RELAT_1, TOPS_1, QUANTAL1, LATTICE3, YELLOW_0, FUNCT_1, ORDERS_1, LATTICES, SEQM_3, YELLOW_6, PROB_1, T_0TOPSP, FUNCT_3, WAYBEL21, CAT_1, ARYTM_3, WAYBEL_7, WAYBEL32, RLVECT_3; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, RELAT_1, FUNCT_1, FINSET_1, STRUCT_0, REALSET1, FUNCT_2, ORDERS_1, LATTICE3, PRE_TOPC, TOPS_1, TOPS_2, CONNSP_2, T_0TOPSP, GROUP_1, YELLOW_0, WAYBEL_0, CANTOR_1, YELLOW_2, WAYBEL_2, YELLOW_6, WAYBEL_9, RELSET_1, WAYBEL11, WAYBEL19, YELLOW_9, WAYBEL21; constructors WAYBEL_1, CANTOR_1, TOPS_1, TOPS_2, WAYBEL_3, TSP_1, WAYBEL11, YELLOW_9, GROUP_1, TOLER_1, WAYBEL_5, WAYBEL21, BORSUK_1, MEMBERED, PARTFUN1; clusters STRUCT_0, LATTICE3, WAYBEL_0, FINSET_1, YELLOW_6, WAYBEL_3, WAYBEL11, WAYBEL21, YELLOW_9, RELSET_1, SUBSET_1, YELLOW14, WAYBEL29, MEMBERED, ZFMISC_1, FUNCT_2, PARTFUN1; requirements SUBSET, BOOLE; definitions TARSKI, WAYBEL_0, WAYBEL11, LATTICE3, WAYBEL_9, XBOOLE_0; theorems YELLOW_9, CANTOR_1, PRE_TOPC, WAYBEL_0, CONNSP_2, WAYBEL11, ZFMISC_1, TARSKI, REALSET1, YELLOW_6, ORDERS_1, TOPS_2, TOPS_1, YELLOW_8, YELLOW_0, RELAT_1, FUNCT_1, YELLOW_2, SUBSET_1, LATTICE3, FINSET_1, WAYBEL_2, SETFAM_1, TSP_1, WAYBEL_9, WAYBEL21, WAYBEL_8, FUNCT_2, RELSET_1, XBOOLE_0, XBOOLE_1; schemes COMPLSP1, FRAENKEL, DOMAIN_1, COMPTS_1, FUNCT_2; begin definition let T be non empty TopRelStr; attr T is upper means :Def1: {(downarrow x)` where x is Element of T: not contradiction} is prebasis of T; end; definition cluster Scott up-complete strict TopLattice; existence proof consider R being complete LATTICE; consider T being strict Scott correct TopAugmentation of R; take T; thus thesis; end; end; definition let T be TopSpace-like non empty reflexive TopRelStr; attr T is order_consistent means :Def2: for x being Element of T holds downarrow x = Cl {x} & for N being eventually-directed net of T st x = sup N for V being a_neighborhood of x holds N is_eventually_in V; end; definition cluster trivial -> upper (non empty reflexive TopSpace-like TopRelStr); coherence proof let T be non empty reflexive TopSpace-like TopRelStr; assume A1: T is trivial; set BB = {(downarrow x)` where x is Element of T: not contradiction}; BB c= bool the carrier of T proof let a be set; assume a in BB; then ex x being Element of T st a = (downarrow x)`; hence thesis; end; then reconsider C = BB as Subset-Family of T by SETFAM_1:def 7; reconsider C as Subset-Family of T; A2: BB c= the topology of T proof let a be set; assume a in BB; then consider x being Element of T such that A3: a = (downarrow x)`; a c= {} proof let y be set; assume A4: y in a; then y in the carrier of T & x <= x by A3; then y = x & x in downarrow x by A1,REALSET1:def 20,WAYBEL_0:17; then x in (downarrow x) /\ a & (downarrow x) misses a by A3,A4,PRE_TOPC:26,XBOOLE_0:def 3; hence thesis by XBOOLE_0:def 7; end; then a = {} by XBOOLE_1:3; hence thesis by PRE_TOPC:5; end; reconsider F = {the carrier of T} as Basis of T by A1,YELLOW_9:10; BB = {{}} proof thus BB c= {{}} proof let a be set; assume a in BB; then consider x being Element of T such that A5: a = (downarrow x)`; x <= x; then the carrier of T = {x} & x in downarrow x by A1,WAYBEL_0:17,YELLOW_9:9; then a = {} or a = the carrier of T & not x in a by A5,YELLOW_6:10,ZFMISC_1:39; hence thesis by TARSKI:def 1; end; consider x being Element of T; x <= x; then the carrier of T = {x} & x in downarrow x by A1,WAYBEL_0:17, YELLOW_9:9; then (downarrow x)` = {} or (downarrow x)` = the carrier of T & not x in (downarrow x)` by YELLOW_6:10,ZFMISC_1:39; then {} in BB; hence thesis by ZFMISC_1:37; end; then FinMeetCl C = {{}, the carrier of T} by YELLOW_9:11; then F c= FinMeetCl C by ZFMISC_1:12; hence BB is prebasis of T by A2,CANTOR_1:def 5; end; end; definition cluster upper trivial up-complete strict TopLattice; existence proof consider T being trivial up-complete strict TopLattice; take T; thus thesis; end; end; theorem Th1: for T being upper up-complete (non empty TopPoset) for A being Subset of T st A is open holds A is upper proof let T be upper up-complete (non empty TopPoset); let A be Subset of T such that A1: A is open; A2: A in the topology of T by A1,PRE_TOPC:def 5; reconsider BB = {(downarrow x)` where x is Element of T: not contradiction} as prebasis of T by Def1; consider F being Basis of T such that A3: F c= FinMeetCl BB by CANTOR_1:def 5; the topology of T c= UniCl F by CANTOR_1:def 2; then consider Y being Subset-Family of T such that A4: Y c= F & A = union Y by A2,CANTOR_1:def 1; let x,y be Element of T; assume x in A; then consider Z being set such that A5: x in Z & Z in Y by A4,TARSKI:def 4; Z in F by A4,A5; then consider X being Subset-Family of T such that A6: X c= BB & X is finite & Z = Intersect X by A3,CANTOR_1:def 4; assume A7: x <= y; now let Q be set; assume A8: Q in X; then Q in BB by A6; then consider z being Element of T such that A9: Q = (downarrow z)`; x in Q & (downarrow z) misses Q by A5,A6,A8,A9,CANTOR_1:10,PRE_TOPC :26; then not x in downarrow z by XBOOLE_0:3; then not x <= z by WAYBEL_0:17; then not y <= z by A7,ORDERS_1:26; then not y in downarrow z by WAYBEL_0:17; then y in (the carrier of T) \ downarrow z & the carrier of T = [#]T by PRE_TOPC:12,XBOOLE_0:def 4; hence y in Q by A9,PRE_TOPC:17; end; then y in Z by A6,CANTOR_1:10; hence thesis by A4,A5,TARSKI:def 4; end; theorem for T being up-complete (non empty TopPoset) holds T is upper implies T is order_consistent proof let T be up-complete (non empty TopPoset); assume A1: T is upper; then reconsider BB = {(downarrow x)` where x is Element of T: not contradiction} as prebasis of T by Def1; for x being Element of T holds downarrow x = Cl {x} & for N being eventually-directed net of T st x = sup N for V being a_neighborhood of x holds N is_eventually_in V proof let x be Element of T; thus downarrow x = Cl {x} proof thus downarrow x c= Cl {x} proof let a be set; assume A2:a in downarrow x; then reconsider a' = a as Point of T; for G being Subset of T st G is open holds a' in G implies {x} meets G proof let G be Subset of T such that A3: G is open;assume A4: a' in G; reconsider v = a' as Element of T; A5: v <= x by A2,WAYBEL_0:17; G is upper by A1,A3,Th1; then A6: x in G by A4,A5,WAYBEL_0:def 20; x in {x} by TARSKI:def 1; hence {x} meets G by A6,XBOOLE_0:3; end; hence a in Cl {x} by PRE_TOPC:54; end; thus Cl {x} c= downarrow x proof let a be set;assume A7: a in Cl{x}; reconsider BB as Subset-Family of T; A8: (downarrow x)` in BB; BB is open by YELLOW_9:28; then A9: (downarrow x)` is open by A8,TOPS_2:def 1; (downarrow x)` = [#]T\downarrow x by PRE_TOPC:17; then A10: downarrow x is closed by A9,PRE_TOPC:def 6; x <= x; then x in downarrow x by WAYBEL_0:17; then {x} c= downarrow x by ZFMISC_1:37; hence a in downarrow x by A7,A10,PRE_TOPC:45; end; end; thus for N being eventually-directed net of T st x = sup N for V being a_neighborhood of x holds N is_eventually_in V proof let N be eventually-directed net of T such that A11: x = sup N; A12: x = Sup the mapping of N by A11,WAYBEL_2:def 1 .= sup rng the mapping of N by YELLOW_2:def 5 .= sup rng netmap (N,T) by WAYBEL_0:def 7; let V be a_neighborhood of x; A13: x in Int V by CONNSP_2:def 1; FinMeetCl BB is Basis of T by YELLOW_9:23; then A14: the topology of T = UniCl FinMeetCl BB by YELLOW_9:22; Int V is open by TOPS_1:51; then Int V in the topology of T by PRE_TOPC:def 5; then consider Y being Subset-Family of T such that A15: Y c= FinMeetCl BB & Int V = union Y by A14,CANTOR_1:def 1; consider Y1 being set such that A16: x in Y1 & Y1 in Y by A13,A15,TARSKI:def 4; consider Z being Subset-Family of T such that A17: Z c= BB & Z is finite & Y1 = Intersect Z by A15,A16,CANTOR_1:def 4; reconsider rngN = rng netmap (N,T) as Subset of T; rngN is directed by WAYBEL_2:18; then ex a being Element of T st a is_>=_than rngN & for b being Element of T st b is_>=_than rngN holds a <= b by WAYBEL_0:def 39; then A18: ex_sup_of rngN,T by YELLOW_0:15; A19: rngN = rng the mapping of N by WAYBEL_0:def 7; defpred P[set,set] means for i,j being Element of N st i = $2 & j >= i holds N.j in $1; A20: for Q being set st Q in Z ex b being set st b in the carrier of N & P[Q,b] proof let Q be set; assume A21: Q in Z; then Q in BB by A17; then consider v1 being Element of T such that A22: Q = (downarrow v1)`; x in (downarrow v1)` by A16,A17,A21,A22,CANTOR_1:10; then x in [#]T\downarrow v1 by PRE_TOPC:17; then x in [#]T & not x in downarrow v1 by XBOOLE_0:def 4; then A23: x in [#]T & not x <= v1 by WAYBEL_0:17; not (rngN c= downarrow v1) proof assume A24: rngN c= downarrow v1; ex_sup_of downarrow v1,T by WAYBEL_0:34; then sup rngN <= sup downarrow v1 by A18,A24,YELLOW_0:34 ; hence contradiction by A12,A23,WAYBEL_0:34; end; then consider w be set such that A25: w in rngN & not w in downarrow v1 by TARSKI:def 3; reconsider w' = w as Element of T by A25; w' in the carrier of T; then w' in [#]T by PRE_TOPC:12; then w' in [#]T\downarrow v1 by A25,XBOOLE_0:def 4; then A26: w' in Q by A22,PRE_TOPC:17; consider i being set such that A27: i in dom the mapping of N and A28: w' = (the mapping of N).i by A19,A25,FUNCT_1:def 5; reconsider i as Element of N by A27; A29: i in the carrier of N & N.i in Q by A26,A28,WAYBEL_0:def 8; consider b being Element of N such that A30: for l being Element of N st b <= l holds N.i <= N.l by WAYBEL_0:11; take b; thus b in the carrier of N; thus for j,k being Element of N st j = b & k >= j holds N.k in Q proof let j,k be Element of N such that A31: j = b & k >= j; A32: N.i <= N.k by A30,A31; N.k in the carrier of T; then A33: N.k in [#]T by PRE_TOPC:12; N.i in [#]T\downarrow v1 by A22,A29,PRE_TOPC:17; then N.i in [#]T & not N.i in downarrow v1 by XBOOLE_0:def 4; then N.i in [#]T & not N.i <= v1 by WAYBEL_0:17; then not N.k <= v1 by A32,ORDERS_1:26; then not N.k in downarrow v1 by WAYBEL_0:17; then N.k in [#]T\downarrow v1 by A33,XBOOLE_0:def 4; hence N.k in Q by A22,PRE_TOPC:17; end; end; consider f be Function such that A34: dom f = Z & rng f c= the carrier of N and A35: for Q being set st Q in Z holds P[Q,f.Q] from NonUniqBoundFuncEx(A20); reconsider rngf = rng f as finite Subset of [#]N by A17,A34,FINSET_1:26, PRE_TOPC:12; [#]N is directed by WAYBEL_0:def 6; then consider k being Element of N such that A36: k in [#]N & k is_>=_than rngf by WAYBEL_0:1; take k; let k1 be Element of N such that A37: k <= k1; now let Q be set; assume A38: Q in Z; then A39: f.Q in rngf by A34,FUNCT_1:def 5; then reconsider j = f.Q as Element of N by A34; j <= k by A36,A39,LATTICE3:def 9; then j <= k1 by A37,ORDERS_1:26; hence N.k1 in Q by A35,A38; end; then N.k1 in Y1 & Y1 c= union Y by A16,A17,CANTOR_1:10,ZFMISC_1:92; then N.k1 in Int V & Int V c= V by A15,TOPS_1:44; hence N.k1 in V; end; end; hence T is order_consistent by Def2; end; canceled 4; theorem Th7: for R being up-complete (non empty reflexive transitive antisymmetric RelStr) ex T being TopAugmentation of R st T is Scott proof let R be up-complete (non empty reflexive transitive antisymmetric RelStr); set To = {A where A is Subset of R:A is inaccessible upper}; To c= bool the carrier of R proof let a be set; assume a in To; then ex y being Subset of R st a = y & y is inaccessible upper; hence thesis; end; then reconsider top = To as Subset-Family of R by SETFAM_1:def 7; reconsider top as Subset-Family of R; TopRelStr(#the carrier of R, the InternalRel of R, top#) is TopAugmentation of R proof the RelStr of TopRelStr(#the carrier of R, the InternalRel of R, top#) = the RelStr of R; hence thesis by YELLOW_9:def 4; end; then reconsider T=TopRelStr(#the carrier of R, the InternalRel of R, top#) as TopAugmentation of R; take T; thus T is Scott proof let S be Subset of T; thus S is open implies S is inaccessible upper proof assume S is open; then S in the topology of T by PRE_TOPC:def 5; then consider Y being Subset of R such that A1: S = Y & Y is inaccessible upper; the RelStr of R = the RelStr of T; hence S is inaccessible upper by A1,WAYBEL_0:25,YELLOW_9:47; end; assume A2: S is inaccessible upper; A3: the RelStr of R = the RelStr of T; reconsider S' = S as Subset of R; S' is inaccessible proof let D be non empty directed Subset of R such that A4: sup D in S'; reconsider E = D as Subset of T; ex a being Element of R st a is_>=_than D & for b being Element of R st b is_>=_than D holds a <= b by WAYBEL_0:def 39; then ex_sup_of D,R by YELLOW_0:15; then E is directed & sup D = sup E by A3,WAYBEL_0:3,YELLOW_0:26; hence D meets S' by A2,A4,WAYBEL11:def 1; end; then S' is inaccessible upper by A2,A3,WAYBEL_0:25; then S' in top; hence S is open by PRE_TOPC:def 5; end; end; theorem Th8: for R being up-complete (non empty Poset) for T being TopAugmentation of R holds T is Scott implies T is correct proof let R be up-complete (non empty Poset), T be TopAugmentation of R; assume T is Scott; then reconsider T as Scott TopAugmentation of R; T is correct; hence thesis; end; definition let R be up-complete (non empty reflexive transitive antisymmetric RelStr); cluster Scott -> correct TopAugmentation of R; coherence by Th8; end; definition let R be up-complete (non empty reflexive transitive antisymmetric RelStr); cluster Scott correct TopAugmentation of R; existence proof consider T being TopAugmentation of R such that A1: T is Scott by Th7; take T; thus thesis by A1,Th8; end; end; theorem Th9: :: Remark 1.4 (ii) for T being Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr), x being Element of T holds Cl {x} = downarrow x proof let T be Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr), x be Element of T; reconsider T' = T as Scott TopAugmentation of T by YELLOW_9:44; reconsider dx = downarrow x as Subset of T'; reconsider A = {x} as Subset of T'; A1: downarrow x is closed by WAYBEL11:11; x <= x; then x in downarrow x by WAYBEL_0:17; then A2: {x} c= downarrow x by ZFMISC_1:37; now let C be Subset of T' such that A3: A c= C; reconsider D = C as Subset of T'; assume C is closed; then A4: D is lower by WAYBEL11:7; x in C by A3,ZFMISC_1:37; hence dx c= C by A4,WAYBEL11:6; end; hence Cl {x} = downarrow x by A1,A2,YELLOW_8:17; end; theorem Th10: for T being up-complete Scott (non empty TopPoset) holds T is order_consistent proof let T be up-complete Scott (non empty TopPoset); for x being Element of T holds downarrow x = Cl {x} & for N being eventually-directed net of T st x = sup N for V being a_neighborhood of x holds N is_eventually_in V proof let x be Element of T; for N being eventually-directed net of T st x = sup N for V being a_neighborhood of x holds N is_eventually_in V proof let N be eventually-directed net of T such that A1: x = sup N; x = Sup the mapping of N by A1,WAYBEL_2:def 1; then x = sup rng the mapping of N by YELLOW_2:def 5; then A2: x = sup rng netmap (N,T) by WAYBEL_0:def 7; let V be a_neighborhood of x; A3: x in Int V by CONNSP_2:def 1; A4: Int V is open by TOPS_1:51; then A5: Int V is inaccessible by WAYBEL11:def 4; A6: Int V is upper Subset of T by A4,WAYBEL11:def 4; reconsider rngN = rng netmap (N,T) as Subset of T; rngN is directed by WAYBEL_2:18; then Int V meets rngN by A2,A3,A5,WAYBEL11:def 1; then consider z being set such that A7: z in Int V & z in rngN by XBOOLE_0:3; reconsider z' = z as Element of T by A7; rngN = rng the mapping of N by WAYBEL_0:def 7; then consider i being set such that A8: i in dom the mapping of N and A9: z' = (the mapping of N).i by A7,FUNCT_1:def 5; reconsider i as Element of N by A8; A10: z' = N.i by A9,WAYBEL_0:def 8; consider j being Element of N such that A11: for k being Element of N st j <= k holds N.i <= N.k by WAYBEL_0:11; take j; let l be Element of N such that A12: j <= l; N.i <= N.l by A11,A12; then A13: N.l in Int V by A6,A7,A10,WAYBEL_0:def 20; Int V c= V by TOPS_1:44; hence N.l in V by A13; end; hence thesis by Th9; end; hence T is order_consistent by Def2; end; theorem Th11: for R being /\-complete Semilattice, Z be net of R, D be Subset of R st D = {"/\"({Z.k where k is Element of Z: k >= j},R) where j is Element of Z: not contradiction} holds D is non empty directed proof let R be /\-complete Semilattice, Z be net of R, D be Subset of R; assume A1: D = {"/\"({Z.k where k is Element of Z: k >= j},R) where j is Element of Z: not contradiction}; consider j being Element of Z; "/\"({Z.k where k is Element of Z: k >= j},R) in D by A1; hence D is non empty; let x,y be Element of R; assume x in D; then consider jx being Element of Z such that A2: x = "/\"({Z.k where k is Element of Z: k >= jx},R) by A1; assume y in D; then consider jy being Element of Z such that A3: y = "/\"({Z.k where k is Element of Z: k >= jy},R) by A1; reconsider jx, jy as Element of Z; consider j being Element of Z such that A4: j >= jx and A5: j >= jy by YELLOW_6:def 5; consider j' being Element of Z such that A6: j' >= j & j' >= j by YELLOW_6:def 5; deffunc F(Element of Z) = Z.$1; defpred Px[Element of Z] means $1 >= jx; defpred Py[Element of Z] means $1 >= jy; defpred P[Element of Z] means $1 >= j; set Ex = {F(k) where k is Element of Z: Px[k]}, Ey = {F(k) where k is Element of Z: Py[k]}, E = {F(k) where k is Element of Z: P[k]}; A7: Z.j in Ex by A4; A8: Z.j in Ey by A5; A9: Z.j' in E by A6; A10: Ex is Subset of R from SubsetFD; A11: Ey is Subset of R from SubsetFD; A12: E is Subset of R from SubsetFD; take z = "/\"({Z.k where k is Element of Z: k >= j},R); reconsider Ex'= Ex as non empty Subset of R by A7,A10; reconsider Ey' = Ey as non empty Subset of R by A8,A11; reconsider E' = E as non empty Subset of R by A9,A12; A13: ex_inf_of E',R & ex_inf_of Ex',R & ex_inf_of Ey',R by WAYBEL_0:76; thus z in D by A1; E' c= Ex' proof let e be set; assume e in E'; then consider k being Element of Z such that A14: e = Z.k and A15: k >= j; reconsider k as Element of Z; k >= jx by A4,A15,YELLOW_0:def 2; hence e in Ex' by A14; end; hence x <= z by A2,A13,YELLOW_0:35; E' c= Ey' proof let e be set; assume e in E'; then consider k being Element of Z such that A16: e = Z.k and A17: k >= j; reconsider k as Element of Z; k >= jy by A5,A17,YELLOW_0:def 2; hence e in Ey' by A16; end; hence y <= z by A3,A13,YELLOW_0:35; end; theorem Th12: for R being /\-complete Semilattice, S being Subset of R, a being Element of R holds a in S implies "/\"(S,R) <= a proof let R be /\-complete Semilattice, S be Subset of R; let a be Element of R; assume A1: a in S; then ex_inf_of S,R by WAYBEL_0:76; then S is_>=_than "/\"(S, R) by YELLOW_0:31; hence "/\"(S, R) <= a by A1,LATTICE3:def 8; end; theorem Th13: for R being /\-complete Semilattice, N being monotone reflexive net of R holds lim_inf N = sup N proof let R be /\-complete Semilattice, N be monotone reflexive net of R; deffunc F(Element of N) = "/\"({N.i where i is Element of N: i >= $1},R); deffunc G(Element of N) = N.$1; defpred P[set] means not contradiction; set X = {F(j) where j is Element of N: P[j]}; A1: for j being Element of N holds G(j) = F(j) proof let j be Element of N; defpred P[Element of N] means $1 >= j; set Y = {G(i) where i is Element of N: P[i]}; j <= j; then A2: N.j in Y; Y is Subset of R from SubsetFD; then Y is non empty Subset of R by A2; then A3: ex_inf_of Y,R by WAYBEL_0:76; A4: N.j is_<=_than Y proof let y be Element of R; assume y in Y; then ex i being Element of N st y = N.i & j <= i; hence N.j <= y by WAYBEL11:def 9; end; for b being Element of R st b is_<=_than Y holds N.j >= b proof let b be Element of R; assume A5: b is_<=_than Y; reconsider j' = j as Element of N; j' <= j'; then N.j' in Y; hence N.j >= b by A5,LATTICE3:def 8; end; hence N.j = "/\"(Y,R) by A3,A4,YELLOW_0:def 10; end; rng the mapping of N = {G(j) where j is Element of N: P[j]} by WAYBEL11:19 .= X from FraenkelF'(A1); hence lim_inf N = "\/"(rng the mapping of N,R) by WAYBEL11:def 6 .= Sup the mapping of N by YELLOW_2:def 5 .= sup N by WAYBEL_2:def 1; end; theorem Th14: for R being /\-complete Semilattice for S being Subset of R holds S in the topology of ConvergenceSpace Scott-Convergence R iff S is inaccessible upper proof let R be /\-complete Semilattice; set SC = Scott-Convergence R, T = ConvergenceSpace SC; A1: the topology of T = { V where V is Subset of R: for p being Element of R st p in V for N being net of R st [N,p] in SC holds N is_eventually_in V} by YELLOW_6:def 27; let S be Subset of R; hereby assume S in the topology of T; then consider V being Subset of R such that A2: S = V and A3: for p being Element of R st p in V for N being net of R st [N,p] in SC holds N is_eventually_in V by A1; thus S is inaccessible proof let D be non empty directed Subset of R such that A4: sup D in S; A5: dom id D = D & rng id D = D by RELAT_1:71; then reconsider f = id D as Function of D, the carrier of R by FUNCT_2:def 1,RELSET_1:11; reconsider N = Net-Str(D,f) as strict monotone reflexive net of R by A5,WAYBEL11:20; A6: N in NetUniv R by WAYBEL11:21; lim_inf N = sup N by Th13 .= Sup the mapping of N by WAYBEL_2:def 1 .= "\/"(rng the mapping of N,R) by YELLOW_2:def 5 .= "\/"(rng f,R) by WAYBEL11:def 10 .= sup D by RELAT_1:71; then sup D is_S-limit_of N by WAYBEL11:def 7; then [N,sup D] in SC by A6,WAYBEL11:def 8; then N is_eventually_in S by A2,A3,A4; then consider i0 being Element of N such that A7: for j being Element of N st i0 <= j holds N.j in S by WAYBEL_0:def 11; consider j0 being Element of N such that A8: j0 >= i0 and j0 >= i0 by YELLOW_6:def 5; A9: N.j0 in S by A7,A8; A10: D = the carrier of N by WAYBEL11:def 10; N.j0 = (the mapping of N).j0 by WAYBEL_0:def 8 .= (id D).j0 by WAYBEL11:def 10 .= j0 by A10,FUNCT_1:35; hence D meets S by A9,A10,XBOOLE_0:3; end; thus S is upper proof let x,y be Element of R such that A11: x in S and A12: x <= y; A13: Net-Str y in NetUniv R by WAYBEL11:29; y = lim_inf Net-Str y by WAYBEL11:28; then x is_S-limit_of Net-Str y by A12,WAYBEL11:def 7; then [Net-Str y,x] in SC by A13,WAYBEL11:def 8; then Net-Str y is_eventually_in S by A2,A3,A11; hence y in S by WAYBEL11:27; end; end; assume that A14: S is inaccessible and A15: S is upper; for p being Element of R st p in S for N being net of R st [N,p] in SC holds N is_eventually_in S proof let p be Element of R such that A16: p in S; reconsider p' = p as Element of R; let N be net of R; assume A17: [N,p] in SC; SC c= [:NetUniv R, the carrier of R:] by YELLOW_6:def 21; then A18: N in NetUniv R by A17,ZFMISC_1:106; then ex N' being strict net of R st N' = N & the carrier of N' in the_universe_of the carrier of R by YELLOW_6:def 14 ; then p is_S-limit_of N by A17,A18,WAYBEL11:def 8; then A19: p' <= lim_inf N by WAYBEL11:def 7; deffunc F(Element of N) = "/\"({N.i where i is Element of N: i >= $1},R); defpred P[set] means not contradiction; set X ={F(j) where j is Element of N: P[j]}; X is Subset of R from SubsetFD; then reconsider D = X as Subset of R; reconsider D as non empty directed Subset of R by Th11; lim_inf N = sup D by WAYBEL11:def 6; then sup D in S by A15,A16,A19,WAYBEL_0:def 20; then D meets S by A14,WAYBEL11:def 1; then D /\ S <> {} by XBOOLE_0:def 7; then consider d being Element of R such that A20: d in D /\ S by SUBSET_1:10; reconsider d as Element of R; d in D by A20,XBOOLE_0:def 3; then consider j being Element of N such that A21: d = "/\"({N.i where i is Element of N: i >= j},R); defpred P[Element of N] means $1 >= j; deffunc F(Element of N) = N.$1; {F(i) where i is Element of N: P[i]} is Subset of R from SubsetFD; then reconsider Y = {N.i where i is Element of N: i >= j} as Subset of R; reconsider j as Element of N; take j; let i0 be Element of N; A22: d in S by A20,XBOOLE_0:def 3; assume j <= i0; then N.i0 in Y; then d <= N.i0 by A21,Th12; hence N.i0 in S by A15,A22,WAYBEL_0:def 20; end; hence S in the topology of T by A1; end; theorem Th15: for R being /\-complete up-complete Semilattice, T being TopAugmentation of R st the topology of T = sigma R holds T is Scott proof let R be /\-complete up-complete Semilattice; let T be TopAugmentation of R such that A1: the topology of T = sigma R; A2: the RelStr of T = the RelStr of R by YELLOW_9:def 4; A3: sigma R = the topology of ConvergenceSpace Scott-Convergence R by WAYBEL11:def 12; T is Scott proof let S be Subset of T; reconsider A = S as Subset of R by A2; thus S is open implies S is inaccessible upper proof assume S is open; then S in the topology of T by PRE_TOPC:def 5; then A is inaccessible upper by A1,A3,Th14; hence thesis by A2,WAYBEL_0:25,YELLOW_9:47; end; assume A4:S is inaccessible upper; A is inaccessible proof let D be non empty directed Subset of R such that A5: sup D in A; reconsider E = D as Subset of T by A2; ex a being Element of R st a is_>=_than D & for b being Element of R st b is_>=_than D holds a <= b by WAYBEL_0:def 39; then ex_sup_of D,R by YELLOW_0:15; then E is directed & sup D = sup E by A2,WAYBEL_0:3,YELLOW_0:26; hence D meets A by A4,A5,WAYBEL11:def 1; end; then A is inaccessible upper by A2,A4,WAYBEL_0:25; then A in the topology of T by A1,A3,Th14; hence S is open by PRE_TOPC:def 5; end; hence thesis; end; definition let R be /\-complete up-complete Semilattice; cluster strict Scott correct TopAugmentation of R; existence proof set T = TopRelStr(#the carrier of R, the InternalRel of R, sigma R#); the RelStr of T = the RelStr of R; then reconsider T as TopAugmentation of R by YELLOW_9:def 4; take T; thus thesis by Th15,YELLOW_9:48; end; end; theorem for S being up-complete /\-complete Semilattice, T being Scott TopAugmentation of S holds sigma S = the topology of T proof let S be up-complete /\-complete Semilattice; let T be Scott TopAugmentation of S; set CSC = ConvergenceSpace Scott-Convergence S; thus sigma S c= the topology of T proof let e be set; assume A1: e in sigma S; then A2: e in the topology of CSC by WAYBEL11:def 12; reconsider A = e as Subset of S by A1; A3: the RelStr of S = the RelStr of T by YELLOW_9:def 4; then reconsider A' = A as Subset of T; A is inaccessible upper by A2,Th14; then A' is inaccessible upper by A3,WAYBEL_0:25,YELLOW_9:47; then A' is open by WAYBEL11:def 4; hence e in the topology of T by PRE_TOPC:def 5; end; let e be set;assume A4: e in the topology of T; then reconsider A = e as Subset of T; A is open by A4,PRE_TOPC:def 5; then A5: A is inaccessible upper by WAYBEL11:def 4; A6: the RelStr of S = the RelStr of T by YELLOW_9:def 4; then reconsider A' = A as Subset of S; A' is inaccessible proof let D be non empty directed Subset of S such that A7: sup D in A'; reconsider E = D as Subset of T by A6; ex a being Element of S st a is_>=_than D & for b being Element of S st b is_>=_than D holds a <= b by WAYBEL_0:def 39; then ex_sup_of D,S by YELLOW_0:15; then E is directed & sup D = sup E by A6,WAYBEL_0:3,YELLOW_0:26; hence D meets A' by A5,A7,WAYBEL11:def 1; end; then A' is inaccessible upper by A5,A6,WAYBEL_0:25; then A' in the topology of CSC by Th14; hence thesis by WAYBEL11:def 12; end; theorem :: Remark 1.4 (iii) for T being Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr) holds T is T_0-TopSpace proof let T be Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr); reconsider T' = T as Scott TopAugmentation of T by YELLOW_9:44; now let x,y be Point of T'; reconsider x' = x, y' = y as Element of T'; A1: Cl {x'} = downarrow x' & Cl {y'} = downarrow y' by Th9; assume x <> y; hence Cl {x} <> Cl {y} by A1,WAYBEL_0:19; end; hence thesis by TSP_1:def 5; end; definition let R be up-complete (non empty reflexive transitive antisymmetric RelStr); cluster -> up-complete TopAugmentation of R; coherence; end; theorem Th18: for R being up-complete (non empty reflexive transitive antisymmetric RelStr) for T being Scott TopAugmentation of R, x being Element of T, A being upper Subset of T st not x in A holds (downarrow x)` is a_neighborhood of A proof let R be up-complete (non empty reflexive transitive antisymmetric RelStr), T be Scott TopAugmentation of R, x be Element of T, A be upper Subset of T such that A1: not x in A; downarrow x is closed by WAYBEL11:11; then (downarrow x)` is open by TOPS_1:29; then A2: Int (downarrow x)` = (downarrow x)` by TOPS_1:55; A misses downarrow x by A1,WAYBEL11:5; then A c= (downarrow x)` by PRE_TOPC:21; hence (downarrow x)` is a_neighborhood of A by A2,CONNSP_2:def 2; end; theorem ::Remark 1.4 (iv) for R being up-complete (non empty reflexive transitive antisymmetric TopRelStr) for T being Scott TopAugmentation of R, S being upper Subset of T ex F being Subset-Family of T st S = meet F & for X being Subset of T st X in F holds X is a_neighborhood of S proof let R be up-complete (non empty reflexive transitive antisymmetric TopRelStr), T be Scott TopAugmentation of R, S be upper Subset of T; defpred P[set] means $1 is a_neighborhood of S; set F = { X where X is Subset of T: P[X]}; F is Subset of bool the carrier of T from SubsetD; then F is Subset-Family of T by SETFAM_1:def 7; then reconsider F as Subset-Family of T; take F; thus S = meet F proof [#]T is a_neighborhood of S by YELLOW_6:7; then A1: [#]T in F; now let Z1 be set; assume Z1 in F; then ex X being Subset of T st Z1 = X & X is a_neighborhood of S; hence S c= Z1 by YELLOW_6:8; end; hence S c= meet F by A1,SETFAM_1:6; let x be set such that A2: x in meet F and A3: not x in S; reconsider p = x as Element of T by A2; (downarrow p)` is a_neighborhood of S by A3,Th18; then (downarrow p)` in F; then A4: meet F c= (downarrow p)` by SETFAM_1:4; p <= p; then p in downarrow p by WAYBEL_0:17; hence contradiction by A2,A4,YELLOW_6:10; end; let X be Subset of T; assume X in F; then ex Y being Subset of T st X = Y & Y is a_neighborhood of S; hence X is a_neighborhood of S; end; theorem ::Remark 1.4 (v) for T being Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr), S being Subset of T holds S is open iff S is upper property(S) proof let T be Scott up-complete (non empty reflexive transitive antisymmetric TopRelStr), S be Subset of T; hereby assume A1: S is open; hence A2: S is upper by WAYBEL11:def 4; thus S has_the_property_(S) proof let D be non empty directed Subset of T such that A3: sup D in S; S is inaccessible by A1,WAYBEL11:def 4; then S meets D by A3,WAYBEL11:def 1; then consider y being set such that A4: y in S and A5: y in D by XBOOLE_0:3; reconsider y as Element of T by A4; take y; thus thesis by A2,A4,A5,WAYBEL_0:def 20; end; end; assume that A6: S is upper and A7: S has_the_property_(S); S is inaccessible proof let D be non empty directed Subset of T; assume sup D in S; then consider y being Element of T such that A8: y in D and A9: for x being Element of T st x in D & x >= y holds x in S by A7,WAYBEL11: def 3; y >= y by YELLOW_0:def 1; then y in S by A8,A9; hence D meets S by A8,XBOOLE_0:3; end; hence S is open by A6,WAYBEL11:def 4; end; theorem Th21: for R being up-complete (non empty reflexive transitive antisymmetric TopRelStr), S being non empty directed Subset of R, a being Element of R holds a in S implies a <= "\/"(S, R) proof let R be up-complete (non empty reflexive transitive antisymmetric TopRelStr); let S be non empty directed Subset of R, a be Element of R; assume A1: a in S; ex_sup_of S,R by WAYBEL_0:75; then S is_<=_than "\/"(S, R) by YELLOW_0:30; hence a <= "\/"(S, R) by A1,LATTICE3:def 9; end; ::Remark 1.4 (vi) definition let T be up-complete (non empty reflexive transitive antisymmetric TopRelStr); cluster lower -> property(S) Subset of T; coherence proof let S be Subset of T; assume A1: S is lower; let D be non empty directed Subset of T such that A2: sup D in S; consider y being Element of T such that A3: y in D by SUBSET_1:10; take y; thus y in D by A3; let x be Element of T such that A4: x in D and x >= y; x <= sup D by A4,Th21; hence x in S by A1,A2,WAYBEL_0:def 19; end; end; theorem for T being finite up-complete (non empty Poset), S being Subset of T holds S is inaccessible proof let T be finite up-complete (non empty Poset), S be Subset of T, D be non empty directed Subset of T such that A1: sup D in S; sup D in D proof reconsider D' = D as finite Subset of T; D' c= D'; then reconsider E = D' as finite Subset of D; consider x being Element of T such that A2: x in D and A3: x is_>=_than E by WAYBEL_0:1; A4: for b being Element of T st D is_<=_than b holds b >= x by A2,LATTICE3:def 9; for c being Element of T st D is_<=_than c & for b being Element of T st D is_<=_than b holds b >= c holds c = x proof let c be Element of T such that A5: D is_<=_than c and A6: for b being Element of T st D is_<=_than b holds b >= c; x >= c & c >= x by A2,A3,A5,A6,LATTICE3:def 9; hence c = x by ORDERS_1:25; end; then ex_sup_of D,T by A3,A4,YELLOW_0:def 7; hence sup D in D by A2,A3,A4,YELLOW_0:def 9; end; hence thesis by A1,XBOOLE_0:3; end; theorem Th23: for R being complete connected LATTICE, T being Scott TopAugmentation of R, x being Element of T holds (downarrow x)` is open proof let R be complete connected LATTICE, T be Scott TopAugmentation of R, x be Element of T; reconsider S = downarrow x as directly_closed lower Subset of T by WAYBEL11: 8; S` is open; hence thesis; end; theorem for R being complete connected LATTICE, T being Scott TopAugmentation of R, S being Subset of T holds S is open iff S = the carrier of T or S in {(downarrow x)` where x is Element of T: not contradiction} proof let R be complete connected LATTICE, T be Scott TopAugmentation of R, S be Subset of T; set DD = {(downarrow x)` where x is Element of T: not contradiction}; thus S is open implies S = the carrier of T or S in DD proof assume S is open; then A1: S is inaccessible upper by WAYBEL11:def 4; assume A2: S <> the carrier of T & not S in DD; A3: the carrier of T = [#]T by PRE_TOPC:12; then A4: [#]T\S <> {} by A2,PRE_TOPC:23; A5: the RelStr of T = the RelStr of R by YELLOW_9:def 4; then reconsider K = S` as Subset of R; reconsider D = K as non empty directed Subset of T by A4,A5,PRE_TOPC:17, WAYBEL_0:3; A6: D misses S by PRE_TOPC:21; reconsider x = sup D as Element of T; S` = downarrow x proof thus S` c= downarrow x proof let a be set; assume A7: a in S`; then reconsider A = a as Element of T; x is_>=_than S` by YELLOW_0:32; then A <= x by A7,LATTICE3:def 9; hence thesis by WAYBEL_0:17; end; let a be set; assume A8: a in downarrow x; then reconsider A = a as Element of T; A <= x & not x in S by A1,A6,A8,WAYBEL11:def 1,WAYBEL_0:17; then not A in S by A1,WAYBEL_0:def 20; then A in [#]T\S by A3,XBOOLE_0:def 4; hence thesis by PRE_TOPC:17; end; then (downarrow x)` = ([#]T\S)` by PRE_TOPC:17 .= [#]T\([#]T\S) by PRE_TOPC:17 .= S by PRE_TOPC:22; hence contradiction by A2; end; assume A9: S = the carrier of T or S in DD; per cases by A9; suppose A10: S = the carrier of T; A11: the RelStr of T = the RelStr of R by YELLOW_9:def 4; then S = [#]R by A10,PRE_TOPC:12; then A12: S is inaccessible by A11,YELLOW_9:47; S is upper proof let x,y be Element of T; assume x in S & x <= y; thus y in S by A10; end; hence S is open by A12,WAYBEL11:def 4; suppose S in DD; then consider x being Element of T such that A13: S = (downarrow x)`; thus S is open by A13,Th23; end; definition let R be up-complete (non empty Poset); cluster order_consistent (correct TopAugmentation of R); correctness proof consider T being Scott correct TopAugmentation of R; take T; thus T is order_consistent by Th10; end; end; definition cluster order_consistent complete TopLattice; correctness proof consider T being Scott complete TopLattice; take T; thus thesis by Th10; end; end; theorem Th25: for R being non empty TopRelStr for A being Subset of R holds (for x being Element of R holds downarrow x = Cl {x}) implies (A is open implies A is upper) proof let R be non empty TopRelStr, A be Subset of R; assume A1: for x being Element of R holds downarrow x = Cl {x}; assume A2: A is open; let x,y be Element of R such that A3: x in A and A4: x <= y; x in downarrow y by A4,WAYBEL_0:17; then x in Cl {y} by A1; then A meets {y} by A2,A3,PRE_TOPC:54; then consider z be set such that A5: z in A /\ {y} by XBOOLE_0:4; z in A & z in {y} by A5,XBOOLE_0:def 3; hence y in A by TARSKI:def 1; end; theorem for R being non empty TopRelStr for A being Subset of R holds (for x being Element of R holds downarrow x = Cl {x}) implies for A being Subset of R st A is closed holds A is lower proof let R be non empty TopRelStr, A be Subset of R; assume A1: for x being Element of R holds downarrow x = Cl {x}; let A be Subset of R such that A2: A is closed; let x,y be Element of R such that A3: x in A and A4: y <= x; y in downarrow x by A4,WAYBEL_0:17; then A5: y in Cl {x} by A1; {x} c= A proof let a be set; assume a in {x}; hence a in A by A3,TARSKI:def 1; end; hence y in A by A2,A5,PRE_TOPC:45; end; theorem Th27: for T being up-complete /\-complete LATTICE, N being net of T for i being Element of N holds lim_inf (N|i) = lim_inf N proof let T be complete LATTICE, N be net of T; let i be Element of N; reconsider M = N|i as subnet of N; reconsider e = incl(M,N) as Embedding of M, N by WAYBEL21:40; M is full SubNetStr of N by WAYBEL_9:14; then A1: M is full SubRelStr of N by YELLOW_6:def 9; the carrier of M c= the carrier of N by WAYBEL_9:13; then A2: incl(M,N) = id the carrier of M by YELLOW_9:def 1; now let k be Element of N, j be Element of M; consider j' being Element of N such that A3: j' = j & j' >= i by WAYBEL_9:def 7; assume e.j <= k; then A4: k >= j' by A2,A3,FUNCT_1:35; then k >= i by A3,YELLOW_0:def 2; then k in the carrier of M by WAYBEL_9:def 7; then reconsider k' = k as Element of M; take k'; thus k' >= j by A1,A3,A4,YELLOW_0:61; M.k' = N.(e.k') & M.k' <= M.k' by WAYBEL21:36; hence N.k >= M.k' by A2,FUNCT_1:35; end; hence lim_inf (N|i) = lim_inf N by WAYBEL21:38; end; definition let S be non empty 1-sorted, R be non empty RelStr, f be Function of the carrier of R,the carrier of S; func R*'f -> strict non empty NetStr over S means :Def3: the RelStr of it = the RelStr of R & the mapping of it = f; existence proof reconsider M = NetStr (# the carrier of R,the InternalRel of R, f #) as strict non empty NetStr over S; take M; thus thesis; end; uniqueness; end; definition let S be non empty 1-sorted, R be non empty transitive RelStr, f be Function of the carrier of R,the carrier of S; cluster R*'f -> transitive; coherence proof the RelStr of R*'f = the RelStr of R & R is transitive by Def3; hence R*'f is transitive by WAYBEL_8:13; end; end; definition let S be non empty 1-sorted, R be non empty directed RelStr, f be Function of the carrier of R,the carrier of S; cluster R*'f -> directed; coherence proof A1: the RelStr of R*'f = the RelStr of R & R is directed by Def3; thus [#](R*'f) is directed proof A2: [#]R is directed by WAYBEL_0:def 6; [#](R*'f) = the carrier of R*'f by PRE_TOPC:12 .= [#]R by A1,PRE_TOPC:12; hence thesis by A1,A2,WAYBEL_0:3; end; end; end; definition let R be non empty RelStr, N be prenet of R; func inf_net N -> strict prenet of R means :Def4: ex f being map of N,R st it = N*'f & for i being Element of N holds f.i = "/\"({N.k where k is Element of N: k >= i},R); existence proof deffunc F(Element of N) = "/\"({N.k where k is Element of N: k >= $1},R); consider g being Function of the carrier of N, the carrier of R such that A1: for i being Element of N holds g.i = F(i) from LambdaD; reconsider f = g as map of N,R; reconsider M = N*'f as strict prenet of R; take M; thus thesis by A1; end; uniqueness proof let M, P be strict prenet of R such that A2: ex f being map of N,R st M = N*'f & for i being Element of N holds f.i = "/\"({N.k where k is Element of N: k >= i},R) and A3: ex f being map of N,R st P = N*'f & for i being Element of N holds f.i = "/\"({N.k where k is Element of N: k >= i},R); consider f1 being map of N,R such that A4: M = N*'f1 & for i being Element of N holds f1.i = "/\" ({N.k where k is Element of N: k >= i},R) by A2; consider f2 being map of N,R such that A5: P = N*'f2 & for i being Element of N holds f2.i = "/\" ({N.k where k is Element of N: k >= i},R) by A3; for i being set st i in the carrier of N holds f1.i = f2.i proof let i be set; assume i in the carrier of N; then reconsider i as Element of N; f1.i = "/\" ({N.k where k is Element of N: k >= i},R) by A4 .= f2.i by A5; hence thesis; end; hence M = P by A4,A5,FUNCT_2:18; end; end; definition let R be non empty RelStr, N be net of R; cluster inf_net N -> transitive; coherence proof ex f being map of N,R st inf_net N = N*'f & for i being Element of N holds f.i = "/\"({N.k where k is Element of N: k >= i},R) by Def4; hence thesis; end; end; definition let R be non empty RelStr, N be net of R; cluster inf_net N -> directed; coherence; end; definition let R be /\-complete (non empty reflexive antisymmetric RelStr), N be net of R; cluster inf_net N -> monotone; coherence proof let i,j be Element of inf_net N such that A1: i <= j; consider f being map of N,R such that A2: inf_net N = N*'f & for i being Element of N holds f.i = "/\"({N.k where k is Element of N: k >= i},R) by Def4; A3: the RelStr of inf_net N = the RelStr of N by A2,Def3; then reconsider i'=i,j'=j as Element of N; deffunc F(Element of N) = N.$1; defpred P[Element of N] means $1 >= j'; defpred Q[Element of N] means $1 >= i'; set J= {F(k) where k is Element of N: P[k]}; set I= {F(k) where k is Element of N: Q[k]}; A4: J is Subset of R from SubsetFD; consider j0 being Element of N such that A5: j0 >= j' & j0 >= j' by YELLOW_6:def 5; N.j0 in J by A5; then reconsider J'= J as non empty Subset of R by A4; A6: I is Subset of R from SubsetFD; consider j1 being Element of N such that A7: j1 >= i' & j1 >= i' by YELLOW_6:def 5; N.j1 in I by A7; then reconsider I'= I as non empty Subset of R by A6; A8: ex_inf_of J',R & ex_inf_of I',R by WAYBEL_0:76; A9:J' c= I' proof let a be set; assume A10: a in J'; then reconsider x = a as Element of R; consider k being Element of N such that A11: x = N.k and A12: k >= j' by A10; reconsider i0 = i,j0 = j as Element of inf_net N; reconsider k' = k as Element of N; i0 <= j0 & i' = i0 & j' = j0 by A1; then i' <= j' & j' <= k' by A3,A12,YELLOW_0:1; then i' <= k' by YELLOW_0:def 2; hence a in I' by A11; end; A13: f.i' = "/\"(I,R) & f.j' = "/\"(J,R) by A2; the mapping of (inf_net N) = f by A2,Def3; then (inf_net N).i = f.i' & (inf_net N).j = f.j' by WAYBEL_0:def 8; hence (inf_net N).i <= (inf_net N).j by A8,A9,A13,YELLOW_0:35; end; end; definition let R be /\-complete (non empty reflexive antisymmetric RelStr), N be net of R; cluster inf_net N -> eventually-directed; coherence; end; theorem Th28: for R being non empty RelStr, N being net of R holds rng the mapping of (inf_net N) = {"/\"({N.i where i is Element of N: i >= j},R) where j is Element of N: not contradiction} proof let R be non empty RelStr, N be net of R; set X = {"/\"({N.i where i is Element of N: i >= j},R) where j is Element of N: not contradiction}; consider f being map of N,R such that A1: inf_net N = N*'f & for i being Element of N holds f.i = "/\" ({N.k where k is Element of N: k >= i},R) by Def4; A2: the RelStr of inf_net N = the RelStr of N by A1,Def3; A3: the mapping of (inf_net N) = f by A1,Def3; then A4: the carrier of inf_net N = dom f by FUNCT_2:def 1; thus rng the mapping of inf_net N c= {"/\"({N.i where i is Element of N: i >= j},R) where j is Element of N: not contradiction} proof let e be set; assume e in rng the mapping of inf_net N; then consider u being set such that A5: u in dom f and A6: e = f.u by A3,FUNCT_1:def 5; reconsider u as Element of N by A5; f.u = "/\"({N.k where k is Element of N: k >= u},R) by A1; hence e in X by A6; end; let e be set; assume e in {"/\"({N.i where i is Element of N: i >= j},R) where j is Element of N: not contradiction}; then consider j being Element of N such that A7: e = "/\"({N.i where i is Element of N: i >= j},R); e = (the mapping of inf_net N).j by A1,A3,A7; hence e in rng the mapping of inf_net N by A2,A3,A4,FUNCT_1:def 5; end; theorem Th29: for R being up-complete /\-complete LATTICE, N being net of R holds sup inf_net N = lim_inf N proof let R be up-complete /\-complete LATTICE, N be net of R; defpred P[set] means not contradiction; deffunc F(Element of N) = "/\"({N.l where l is Element of N: l >= $1},R); set X = {F(j) where j is Element of N: P[j]}; X is Subset of R from SubsetFD; then reconsider D = X as Subset of R; reconsider D as non empty directed Subset of R by Th11; sup inf_net N = Sup the mapping of (inf_net N) by WAYBEL_2:def 1 .= sup rng the mapping of (inf_net N) by YELLOW_2:def 5 .= sup D by Th28 .= lim_inf N by WAYBEL11:def 6; hence thesis; end; theorem for R being up-complete /\-complete LATTICE, N being net of R, i being Element of N holds sup inf_net N = lim_inf (N|i) proof let R be up-complete /\-complete LATTICE, N be net of R, i be Element of N; sup inf_net N = lim_inf N by Th29; hence thesis by Th27; end; theorem Th31: for R being /\-complete Semilattice, N being net of R, V being upper Subset of R holds inf_net N is_eventually_in V implies N is_eventually_in V proof let R be /\-complete Semilattice, N be net of R, V be upper Subset of R; consider f being map of N,R such that A1: inf_net N = N*'f & for i being Element of N holds f.i = "/\" ({N.k where k is Element of N: k >= i},R) by Def4; A2: the RelStr of inf_net N = the RelStr of N by A1,Def3; assume inf_net N is_eventually_in V; then consider i being Element of inf_net N such that A3: for j being Element of inf_net N st i <= j holds (inf_net N).j in V by WAYBEL_0:def 11; consider j0 being Element of inf_net N such that A4: i <= j0 & i <= j0 by YELLOW_6:def 5; A5: (inf_net N).j0 in V by A3,A4; reconsider j' = j0 as Element of N by A2; take j'; let j be Element of N such that A6: j' <= j; defpred P[Element of N] means $1 >= j'; deffunc F(Element of N) = N.$1; set E = {F(k) where k is Element of N: P[k]}; E is Subset of R from SubsetFD; then reconsider E as Subset of R; the mapping of (inf_net N) = f by A1,Def3; then A7: (inf_net N).j0 = f.j' by WAYBEL_0:def 8 .= "/\"(E,R) by A1; N.j in E by A6; then "/\"(E,R) <= N.j by Th12; hence N.j in V by A5,A7,WAYBEL_0:def 20; end; theorem for R being /\-complete Semilattice, N being net of R, V being lower Subset of R holds N is_eventually_in V implies inf_net N is_eventually_in V proof let R be /\-complete Semilattice, N be net of R, V be lower Subset of R; consider f being map of N,R such that A1: inf_net N = N*'f & for i being Element of N holds f.i = "/\" ({N.k where k is Element of N: k >= i},R) by Def4; A2: the RelStr of inf_net N = the RelStr of N by A1,Def3; assume N is_eventually_in V; then consider i being Element of N such that A3: for j being Element of N st i <= j holds N.j in V by WAYBEL_0:def 11; reconsider i' = i as Element of inf_net N by A2; take i'; let j be Element of inf_net N such that A4: i' <= j; reconsider j0 = j as Element of N by A2; defpred P[Element of N] means $1 >= j0; deffunc F(Element of N) = N.$1; set E = {F(k) where k is Element of N: P[k]}; consider j1 being Element of N such that A5: j1 >= j0 & j1 >= j0 by YELLOW_6:def 5; E is Subset of R from SubsetFD; then reconsider E as Subset of R; i <= j0 & j0 <= j1 by A2,A4,A5,YELLOW_0:1; then i <= j1 by YELLOW_0:def 2; then A6: N.j1 in V by A3; N.j1 in E by A5; then A7: "/\"(E,R) <= N.j1 by Th12; the mapping of (inf_net N) = f by A1,Def3; then (inf_net N).j = f.j0 by WAYBEL_0:def 8 .= "/\"(E,R) by A1; hence (inf_net N).j in V by A6,A7,WAYBEL_0:def 19; end; theorem Th33: for R being order_consistent up-complete /\-complete (non empty TopLattice) for N being net of R, x being Element of R holds x <= lim_inf N implies x is_a_cluster_point_of N proof let R be order_consistent up-complete /\-complete (non empty TopLattice), N be net of R, x be Element of R; assume A1: x <= lim_inf N; defpred P[Element of N] means not contradiction; deffunc F(Element of N) = "/\"({N.i where i is Element of N:i >= $1}, R); set X = {F(j) where j is Element of N: P[j]}; X is Subset of R from SubsetFD; then reconsider D = X as Subset of R; reconsider D as non empty directed Subset of R by Th11; A2: sup D = lim_inf N by WAYBEL11:def 6; A3: x <= sup D by A1,WAYBEL11:def 6; A4: sup D = sup inf_net N by A2,Th29; let V be a_neighborhood of x; A5: for a being Element of R holds downarrow a = Cl {a} by Def2; A6: Int V is open by TOPS_1:51; then A7: Int V is upper by A5,Th25; x in Int V by CONNSP_2:def 1; then sup D in Int V by A3,A7,WAYBEL_0:def 20; then reconsider W = Int V as a_neighborhood of (sup D) by A6,CONNSP_2:5; A8: Int V c= V by TOPS_1:44; inf_net N is_eventually_in W by A4,Def2; then N is_eventually_in W by A7,Th31; then N is_eventually_in V by A8,WAYBEL_0:8; hence N is_often_in V by YELLOW_6:28; end; theorem for R being order_consistent up-complete /\-complete (non empty TopLattice) for N being eventually-directed net of R, x being Element of R holds x <= lim_inf N iff x is_a_cluster_point_of N proof let R be order_consistent up-complete /\-complete (non empty TopLattice), N be eventually-directed net of R, x be Element of R; thus x <= lim_inf N implies x is_a_cluster_point_of N by Th33; thus x is_a_cluster_point_of N implies x <= lim_inf N proof assume A1: x is_a_cluster_point_of N; defpred P[Element of N] means not contradiction; deffunc F(Element of N) = "/\"({N.i where i is Element of N:i >= $1}, R); set X = {F(j) where j is Element of N: P[j]}; X is Subset of R from SubsetFD; then reconsider D = X as Subset of R; reconsider D as non empty directed Subset of R by Th11; A2: lim_inf N = sup D by WAYBEL11:def 6; for G being Subset of R st G is open holds x in G implies {sup D} meets G proof let G be Subset of R such that A3: G is open; assume x in G; then reconsider G as a_neighborhood of x by A3,CONNSP_2:5; A4: N is_often_in G by A1,WAYBEL_9:def 9; now let i be Element of N; consider j1 being Element of N such that A5: i <= j1 & N.j1 in G by A4, WAYBEL_0:def 12; consider j2 being Element of N such that A6: for k being Element of N st j2 <= k holds N.j1 <= N.k by WAYBEL_0:11; defpred P[Element of N] means $1 >= j2; deffunc F(Element of N) = N.$1; set E = {F(k) where k is Element of N: P[k]}; A7: E is Subset of R from SubsetFD; consider j' being Element of N such that A8: j' >= j2 & j' >= j2 by YELLOW_6:def 5; N.j' in E by A8; then reconsider E' = E as non empty Subset of R by A7; A9: ex_inf_of E',R by WAYBEL_0:76; N.j1 is_<=_than E' proof let b be Element of R such that A10: b in E'; consider k being Element of N such that A11: b = N.k and A12: k >= j2 by A10; reconsider k' = k as Element of N; N.j1 <= N.k' by A6,A12; hence N.j1 <= b by A11; end; then A13: N.j1 <= "/\"(E',R) by A9,YELLOW_0:31; for a being Element of R holds downarrow a = Cl {a} by Def2; then A14: G is upper by A3,Th25; then A15: "/\"(E',R) in G by A5,A13,WAYBEL_0:def 20; "/\"(E',R) in D; then "/\"(E',R) <= sup D by Th21; hence sup D in G by A14,A15,WAYBEL_0:def 20; end; then sup D in G & sup D in {sup D} by TARSKI:def 1; hence thesis by XBOOLE_0:3; end; then x in Cl {sup D} by PRE_TOPC:54; then x in downarrow sup D by Def2; hence x <= lim_inf N by A2,WAYBEL_0:17; end; end;