Copyright (c) 1997 Association of Mizar Users
environ vocabulary ORDERS_1, CAT_1, YELLOW_0, WELLORD1, PRE_TOPC, SGRAPH1, FUNCT_1, RELAT_1, YELLOW_1, WAYBEL_0, LATTICES, RELAT_2, WAYBEL_1, GROUP_6, SEQM_3, WAYBEL_8, COMPTS_1, FINSET_1, BOOLE, LATTICE3, QUANTAL1, WAYBEL_3, ORDINAL2, YELLOW_2, FILTER_2, BINOP_1, BHSP_3, WAYBEL_6, OPPCAT_1, FILTER_0, ZF_LANG, WAYBEL_5, WAYBEL15; notation TARSKI, XBOOLE_0, SUBSET_1, RELAT_1, WELLORD1, FUNCT_1, FUNCT_2, FINSET_1, STRUCT_0, ORDERS_1, PRE_TOPC, QUANTAL1, GRCAT_1, LATTICE3, YELLOW_0, YELLOW_1, YELLOW_2, YELLOW_7, WAYBEL_0, WAYBEL_1, WAYBEL_3, WAYBEL_5, WAYBEL_6, WAYBEL_8; constructors ORDERS_3, TOLER_1, QUANTAL1, TOPS_2, GRCAT_1, YELLOW_3, WAYBEL_1, WAYBEL_3, WAYBEL_5, WAYBEL_6, WAYBEL_8; clusters STRUCT_0, RELSET_1, FINSET_1, FUNCT_1, LATTICE3, YELLOW_0, YELLOW_2, WAYBEL_0, WAYBEL_1, WAYBEL_2, WAYBEL_3, WAYBEL_5, WAYBEL_8, WAYBEL10, SUBSET_1, XBOOLE_0; requirements SUBSET, BOOLE; definitions TARSKI; theorems TARSKI, RELAT_1, FINSET_1, WELLORD1, FUNCT_1, FUNCT_2, ORDERS_1, QUANTAL1, LATTICE3, GRCAT_1, YELLOW_0, YELLOW_1, YELLOW_2, YELLOW_5, YELLOW_6, YELLOW_7, WAYBEL_0, WAYBEL_1, WAYBEL_3, WAYBEL_5, WAYBEL_6, WAYBEL_8, WAYBEL13, EXTENS_1, BORSUK_1, XBOOLE_0, XBOOLE_1, WAYBEL14; schemes YELLOW_2, WAYBEL_3; begin :: Preliminaries theorem Th1: for R be RelStr for S be full SubRelStr of R for T be full SubRelStr of S holds T is full SubRelStr of R proof let R be RelStr; let S be full SubRelStr of R; let T be full SubRelStr of S; reconsider T1 = T as SubRelStr of R by YELLOW_6:16; A1: the InternalRel of S = (the InternalRel of R)|_2 the carrier of S by YELLOW_0:def 14; A2: the carrier of T c= the carrier of S by YELLOW_0:def 13; the InternalRel of T = ((the InternalRel of R)|_2 the carrier of S)|_2the carrier of T by A1,YELLOW_0:def 14 .= (the InternalRel of R)|_2 the carrier of T by A2,WELLORD1:29; then T1 is full by YELLOW_0:def 14; hence T is full SubRelStr of R; end; theorem Th2: for X be 1-sorted, Y,Z be non empty 1-sorted for f be map of X,Y for g be map of Y,Z holds f is onto & g is onto implies g*f is onto proof let X be 1-sorted, Y,Z be non empty 1-sorted; let f be map of X,Y; let g be map of Y,Z; assume that A1: f is onto and A2: g is onto; rng f = the carrier of Y by A1,FUNCT_2:def 3 .= dom g by FUNCT_2:def 1; then rng(g*f) = rng g by RELAT_1:47 .= the carrier of Z by A2,FUNCT_2:def 3; hence g*f is onto by FUNCT_2:def 3; end; theorem Th3: for X be 1-sorted for Y be Subset of X holds (id X).:Y = Y proof let X be 1-sorted; let Y be Subset of X; id X = id the carrier of X by GRCAT_1:def 11; hence thesis by BORSUK_1:3; end; theorem for X be set for a be Element of BoolePoset X holds uparrow a = {Y where Y is Subset of X : a c= Y} proof let X be set; let a be Element of BoolePoset X; A1: uparrow a c= {Y where Y is Subset of X : a c= Y} proof let x be set; assume A2: x in uparrow a; then reconsider x' = x as Element of BoolePoset X; A3: x' is Subset of X by WAYBEL_8:28; a <= x' by A2,WAYBEL_0:18; then a c= x by YELLOW_1:2; hence x in {Y where Y is Subset of X : a c= Y} by A3; end; {Y where Y is Subset of X : a c= Y} c= uparrow a proof let x be set; assume x in {Y where Y is Subset of X : a c= Y}; then consider x' be Subset of X such that A4: x' = x and A5: a c= x'; reconsider x' as Element of BoolePoset X by WAYBEL_8:28; a <= x' by A5,YELLOW_1:2; hence x in uparrow a by A4,WAYBEL_0:18; end; hence thesis by A1,XBOOLE_0:def 10; end; theorem for L be upper-bounded non empty antisymmetric RelStr for a be Element of L holds Top L <= a implies a = Top L proof let L be upper-bounded non empty antisymmetric RelStr; let a be Element of L; assume A1: Top L <= a; a <= Top L by YELLOW_0:45; hence thesis by A1,YELLOW_0:def 3; end; theorem Th6: for S,T be non empty Poset for g be map of S,T for d be map of T,S holds g is onto & [g,d] is Galois implies T,Image d are_isomorphic proof let S,T be non empty Poset; let g be map of S,T; let d be map of T,S; assume that A1: g is onto and A2: [g,d] is Galois; d is one-to-one by A1,A2,WAYBEL_1:26; then (the carrier of Image d)|d is one-to-one by FUNCT_1:99; then A3: corestr(d) is one-to-one by WAYBEL_1:def 16; A4: rng corestr(d) = the carrier of Image d by FUNCT_2:def 3; d is monotone by A2,WAYBEL_1:9; then A5: corestr(d) is monotone by WAYBEL_1:33; now let x,y be Element of T; thus x <= y implies (corestr(d)).x <= (corestr(d)).y by A5,WAYBEL_1:def 2; thus (corestr(d)).x <= (corestr(d)).y implies x <= y proof A6: d.x = (corestr(d)).x & d.y = (corestr(d)).y by WAYBEL_1:32; A7: g is monotone by A2,WAYBEL_1:9; for t be Element of T holds d.t is_minimum_of g"{t} by A1,A2,WAYBEL_1:23; then A8: g*d = id T by WAYBEL_1:24; x in the carrier of T; then A9: x in dom d by FUNCT_2:def 1; y in the carrier of T; then A10: y in dom d by FUNCT_2:def 1; assume (corestr(d)).x <= (corestr(d)).y; then d.x <= d.y by A6,YELLOW_0:60; then g.(d.x) <= g.(d.y) by A7,WAYBEL_1:def 2; then (g*d).x <= g.(d.y) by A9,FUNCT_1:23; then (g*d).x <= (g*d).y by A10,FUNCT_1:23; then (id T).x <= y by A8,GRCAT_1:11; hence x <= y by GRCAT_1:11; end; end; then corestr(d) is isomorphic by A3,A4,WAYBEL_0:66; hence T,Image d are_isomorphic by WAYBEL_1:def 8; end; theorem Th7: for L1,L2,L3 be non empty Poset for g1 be map of L1,L2 for g2 be map of L2,L3 for d1 be map of L2,L1 for d2 be map of L3,L2 st [g1,d1] is Galois & [g2,d2] is Galois holds [g2*g1,d1*d2] is Galois proof let L1,L2,L3 be non empty Poset; let g1 be map of L1,L2; let g2 be map of L2,L3; let d1 be map of L2,L1; let d2 be map of L3,L2; assume that A1: [g1,d1] is Galois and A2: [g2,d2] is Galois; A3: g1 is monotone & d1 is monotone by A1,WAYBEL_1:9; A4: g2 is monotone & d2 is monotone by A2,WAYBEL_1:9; then A5: g2*g1 is monotone by A3,YELLOW_2:14; A6: d1*d2 is monotone by A3,A4,YELLOW_2:14; now let s be Element of L3, t be Element of L1; g1 is Function of the carrier of L1,the carrier of L2 & t in the carrier of L1; then A7: t in dom g1 by FUNCT_2:def 1; d2 is Function of the carrier of L3,the carrier of L2 & s in the carrier of L3; then A8: s in dom d2 by FUNCT_2:def 1; thus s <= (g2*g1).t implies (d1*d2).s <= t proof d1*g1 <= id L1 by A1,WAYBEL_1:19; then A9: (d1*g1).t <= (id L1).t by YELLOW_2:10; assume s <= (g2*g1).t; then s <= g2.(g1.t) by A7,FUNCT_1:23; then d2.s <= g1.t by A2,WAYBEL_1:9; then d1.(d2.s) <= d1.(g1.t) by A3,WAYBEL_1:def 2; then d1.(d2.s) <= (d1*g1).t by A7,FUNCT_1:23; then d1.(d2.s) <= (id L1).t by A9,ORDERS_1:26; then d1.(d2.s) <= t by GRCAT_1:11; hence (d1*d2).s <= t by A8,FUNCT_1:23; end; thus (d1*d2).s <= t implies s <= (g2*g1).t proof id L3 <= g2*d2 by A2,WAYBEL_1:19; then A10: (id L3).s <= (g2*d2).s by YELLOW_2:10; assume (d1*d2).s <= t; then d1.(d2.s) <= t by A8,FUNCT_1:23; then d2.s <= g1.t by A1,WAYBEL_1:9; then g2.(d2.s) <= g2.(g1.t) by A4,WAYBEL_1:def 2; then (g2*d2).s <= g2.(g1.t) by A8,FUNCT_1:23; then (id L3).s <= g2.(g1.t) by A10,ORDERS_1:26; then s <= g2.(g1.t) by GRCAT_1:11; hence s <= (g2*g1).t by A7,FUNCT_1:23; end; end; hence [g2*g1,d1*d2] is Galois by A5,A6,WAYBEL_1:9; end; theorem Th8: for L1,L2 be non empty Poset for f be map of L1,L2 for f1 be map of L2,L1 st f1 = (f qua Function)" & f is isomorphic holds [f,f1] is Galois & [f1,f] is Galois proof let L1,L2 be non empty Poset; let f be map of L1,L2; let f1 be map of L2,L1; assume that A1: f1 = (f qua Function)" and A2: f is isomorphic; A3: f is one-to-one monotone by A2,WAYBEL_0:def 38; f1 is isomorphic by A1,A2,WAYBEL_0:68; then A4: f1 is monotone by WAYBEL_0:def 38; now let t be Element of L2, s be Element of L1; s in the carrier of L1; then A5: s in dom f by FUNCT_2:def 1; t in the carrier of L2; then A6: t in dom f1 by FUNCT_2:def 1; A7: f1*f = id dom f by A1,A3,FUNCT_1:61 .= id (the carrier of L1) by FUNCT_2:def 1 .= id L1 by GRCAT_1:def 11; A8: f*f1 = id rng f by A1,A3,FUNCT_1:61 .= id (the carrier of L2) by A2,WAYBEL_0:66 .= id L2 by GRCAT_1:def 11; thus t <= f.s implies f1.t <= s proof assume t <= f.s; then f1.t <= f1.(f.s) by A4,WAYBEL_1:def 2; then f1.t <= (f1*f).s by A5,FUNCT_1:23; hence f1.t <= s by A7,GRCAT_1:11; end; thus f1.t <= s implies t <= f.s proof assume f1.t <= s; then f.(f1.t) <= f.s by A3,WAYBEL_1:def 2; then (f*f1).t <= f.s by A6,FUNCT_1:23; hence t <= f.s by A8,GRCAT_1:11; end; end; hence [f,f1] is Galois by A3,A4,WAYBEL_1:9; now let t be Element of L1, s be Element of L2; s in the carrier of L2; then A9: s in dom f1 by FUNCT_2:def 1; t in the carrier of L1; then A10: t in dom f by FUNCT_2:def 1; A11: f1*f = id dom f by A1,A3,FUNCT_1:61 .= id (the carrier of L1) by FUNCT_2:def 1 .= id L1 by GRCAT_1:def 11; A12: f*f1 = id rng f by A1,A3,FUNCT_1:61 .= id (the carrier of L2) by A2,WAYBEL_0:66 .= id L2 by GRCAT_1:def 11; thus t <= f1.s implies f.t <= s proof assume t <= f1.s; then f.t <= f.(f1.s) by A3,WAYBEL_1:def 2; then f.t <= (f*f1).s by A9,FUNCT_1:23; hence f.t <= s by A12,GRCAT_1:11; end; thus f.t <= s implies t <= f1.s proof assume f.t <= s; then f1.(f.t) <= f1.s by A4,WAYBEL_1:def 2; then (f1*f).t <= f1.s by A10,FUNCT_1:23; hence t <= f1.s by A11,GRCAT_1:11; end; end; hence [f1,f] is Galois by A3,A4,WAYBEL_1:9; end; theorem Th9: for X be set holds BoolePoset X is arithmetic proof let X be set; now let x,y be Element of CompactSublatt BoolePoset X; reconsider x' = x , y' = y as Element of BoolePoset X by YELLOW_0:59; x' is compact & y' is compact by WAYBEL_8:def 1; then x' is finite & y' is finite by WAYBEL_8:30; then x' /\ y' is finite by FINSET_1:15; then x' "/\" y' is finite by YELLOW_1:17; then x' "/\" y' is compact by WAYBEL_8:30; then x' "/\" y' in the carrier of CompactSublatt BoolePoset X by WAYBEL_8:def 1; then reconsider xy = x' "/\" y' as Element of CompactSublatt BoolePoset X ; x' /\ y' c= x' & x' /\ y' c= y' by XBOOLE_1:17; then x' "/\" y' c= x' & x' "/\" y' c= y' by YELLOW_1:17; then x' "/\" y' <= x' & x' "/\" y' <= y' by YELLOW_1:2; then A1: xy <= x & xy <= y by YELLOW_0:61; now let z be Element of CompactSublatt BoolePoset X; reconsider z' = z as Element of BoolePoset X by YELLOW_0:59; assume z <= x & z <= y; then z' <= x' & z' <= y' by YELLOW_0:60; then z' c= x' & z' c= y' by YELLOW_1:2; then z' c= x' /\ y' by XBOOLE_1:19; then z' c= x' "/\" y' by YELLOW_1:17; then z' <= x' "/\" y' by YELLOW_1:2; hence xy >= z by YELLOW_0:61; end; hence ex_inf_of {x,y},CompactSublatt BoolePoset X by A1,YELLOW_0:19; end; then CompactSublatt BoolePoset X is with_infima by YELLOW_0:21; hence BoolePoset X is arithmetic by WAYBEL_8:21; end; definition let X be set; cluster BoolePoset X -> arithmetic; coherence by Th9; end; Lm1: for L1,L2 be non empty RelStr for f be map of L1,L2 holds f is sups-preserving implies f is directed-sups-preserving proof let L1,L2 be non empty RelStr; let f be map of L1,L2; assume f is sups-preserving; then for X be Subset of L1 st X is non empty directed holds f preserves_sup_of X by WAYBEL_0:def 33; hence f is directed-sups-preserving by WAYBEL_0:def 37; end; theorem Th10: for L1,L2 be up-complete (non empty Poset) for f be map of L1,L2 st f is isomorphic for x be Element of L1 holds f.:(waybelow x) = waybelow f.x proof let L1,L2 be up-complete (non empty Poset); let f be map of L1,L2; assume A1: f is isomorphic; then A2: f is one-to-one by WAYBEL_0:def 38; reconsider g = (f qua Function)" as map of L2,L1 by A1,WAYBEL_0:67; let x be Element of L1; A3: f.:(waybelow x) c= waybelow f.x proof let z be set; assume z in f.:(waybelow x); then consider v be set such that v in dom f and A4: v in waybelow x and A5: z = f.v by FUNCT_1:def 12; v in { y where y is Element of L1 : y << x } by A4,WAYBEL_3:def 3; then consider v1 be Element of L1 such that A6: v1 = v and A7: v1 << x; f.v1 << f.x by A1,A7,WAYBEL13:27; hence z in waybelow f.x by A5,A6,WAYBEL_3:7; end; waybelow f.x c= f.:(waybelow x) proof let z be set; assume z in waybelow f.x; then z in { y where y is Element of L2 : y << f.x } by WAYBEL_3:def 3; then consider z1 be Element of L2 such that A8: z1 = z and A9: z1 << f.x; g.z1 in the carrier of L1 & the carrier of L2 is non empty; then A10: g.z1 in dom f by FUNCT_2:def 1; z1 in the carrier of L2 & the carrier of L1 is non empty; then z1 in dom g by FUNCT_2:def 1; then z1 in rng f by A2,FUNCT_1:55; then A11: z1 = f.(g.z1) by A2,FUNCT_1:57; then g.z1 << x by A1,A9,WAYBEL13:27; then g.z1 in waybelow x by WAYBEL_3:7; hence z in f.:(waybelow x) by A8,A10,A11,FUNCT_1:def 12; end; hence f.:(waybelow x) = waybelow f.x by A3,XBOOLE_0:def 10; end; theorem Th11: for L1,L2 be non empty Poset st L1,L2 are_isomorphic & L1 is continuous holds L2 is continuous proof let L1,L2 be non empty Poset; assume that A1: L1,L2 are_isomorphic and A2: L1 is continuous; consider f be map of L1,L2 such that A3: f is isomorphic by A1,WAYBEL_1:def 8; A4: f is one-to-one by A3,WAYBEL_0:def 38; reconsider g = (f qua Function)" as map of L2,L1 by A3,WAYBEL_0:67; A5: g is isomorphic by A3,WAYBEL_0:68; A6: (for x be Element of L1 holds waybelow x is non empty directed) & L1 is up-complete satisfying_axiom_of_approximation by A2,WAYBEL_3:def 6; then A7: L2 is up-complete by A1,WAYBEL13:30; A8: L1 is up-complete (non empty Poset) & L2 is up-complete (non empty Poset) by A1,A6,WAYBEL13:30; now let y be Element of L2; f is sups-preserving by A3,WAYBEL13:20; then A9: f preserves_sup_of waybelow (g.y) by WAYBEL_0:def 33; waybelow (g.y) is non empty directed Subset of L1 by A2,WAYBEL_3:def 6; then A10: ex_sup_of waybelow (g.y),L1 by A6,WAYBEL_0:75; y in the carrier of L2; then A11: y in rng f by A3,WAYBEL_0:66; hence y = f.(g.y) by A4,FUNCT_1:57 .= f.(sup waybelow (g.y)) by A6,WAYBEL_3:def 5 .= sup (f.:(waybelow (g.y))) by A9,A10,WAYBEL_0:def 31 .= sup waybelow f.(g.y) by A3,A8,Th10 .= sup waybelow y by A4,A11,FUNCT_1:57; end; then A12: L2 is satisfying_axiom_of_approximation by WAYBEL_3:def 5; now let y be Element of L2; for Y be finite Subset of waybelow y ex z be Element of L2 st z in waybelow y & z is_>=_than Y proof let Y be finite Subset of waybelow y; now let u be set; assume u in g.:Y; then consider v be set such that v in dom g and A13: v in Y and A14: u = g.v by FUNCT_1:def 12; v in waybelow y by A13; then v in { k where k is Element of L2 : k << y } by WAYBEL_3:def 3; then consider v1 be Element of L2 such that A15: v1 = v and A16: v1 << y; g.v1 << g.y by A5,A8,A16,WAYBEL13:27; hence u in waybelow g.y by A14,A15,WAYBEL_3:7; end; then reconsider X = g.:Y as finite Subset of waybelow g.y by TARSKI:def 3; waybelow g.y is non empty directed by A2,WAYBEL_3:def 6; then consider x be Element of L1 such that A17: x in waybelow g.y and A18: x is_>=_than X by WAYBEL_0:1; take z = f.x; y in the carrier of L2; then y in rng f by A3,WAYBEL_0:66; then A19: f.(g.y) = y by A4,FUNCT_1:57; x << g.y by A17,WAYBEL_3:7; then z << y by A3,A8,A19,WAYBEL13:27; hence z in waybelow y by WAYBEL_3:7; Y c= the carrier of L2 by XBOOLE_1:1; then A20: Y c= rng f by A3,WAYBEL_0:66; f.:X = f.:(f"Y) by A4,FUNCT_1:155 .= Y by A20,FUNCT_1:147; hence z is_>=_than Y by A3,A18,WAYBEL13:19; end; hence waybelow y is non empty directed by WAYBEL_0:1; end; hence L2 is continuous by A7,A12,WAYBEL_3:def 6; end; theorem Th12: for L1,L2 be LATTICE st L1,L2 are_isomorphic & L1 is lower-bounded arithmetic holds L2 is arithmetic proof let L1,L2 be LATTICE; assume that A1: L1,L2 are_isomorphic and A2: L1 is lower-bounded arithmetic; consider f be map of L1,L2 such that A3: f is isomorphic by A1,WAYBEL_1:def 8; reconsider g = (f qua Function)" as map of L2,L1 by A3,WAYBEL_0:67; A4: g is isomorphic by A3,WAYBEL_0:68; L1 is algebraic by A2,WAYBEL_8:def 5; then A5: L2 is algebraic by A1,A2,WAYBEL13:32; A6: L1 is arithmetic LATTICE by A2; then A7: L2 is up-complete LATTICE by A1,WAYBEL13:30; now let x2,y2 be Element of L2; assume that A8: x2 in the carrier of CompactSublatt L2 and A9: y2 in the carrier of CompactSublatt L2 and A10: ex_inf_of {x2,y2},L2; x2 is compact & y2 is compact by A8,A9,WAYBEL_8:def 1; then g.x2 is compact & g.y2 is compact by A4,A6,A7,WAYBEL13:28; then A11: g.x2 in the carrier of CompactSublatt L1 & g.y2 in the carrier of CompactSublatt L1 by WAYBEL_8:def 1; x2 in the carrier of L2 & y2 in the carrier of L2 & the carrier of L1 is non empty; then A12: x2 in dom g & y2 in dom g by FUNCT_2:def 1; g is infs-preserving by A4,WAYBEL13:20; then A13: g preserves_inf_of {x2,y2} by WAYBEL_0:def 32; then A14: g.(inf {x2,y2}) = inf (g.:{x2,y2}) by A10,WAYBEL_0:def 30 .= inf {g.x2,g.y2} by A12,FUNCT_1:118; ex_inf_of g.:{x2,y2},L1 by A10,A13,WAYBEL_0:def 30; then A15: ex_inf_of {g.x2,g.y2},L1 by A12,FUNCT_1:118; CompactSublatt L1 is meet-inheriting by A2,WAYBEL_8:def 5; then inf {g.x2,g.y2} in the carrier of CompactSublatt L1 by A11,A15,YELLOW_0:def 16; then inf {g.x2,g.y2} is compact by WAYBEL_8:def 1; then inf {x2,y2} is compact by A4,A6,A7,A14,WAYBEL13:28; hence inf {x2,y2} in the carrier of CompactSublatt L2 by WAYBEL_8:def 1; end; then CompactSublatt L2 is meet-inheriting by YELLOW_0:def 16; hence L2 is arithmetic by A5,WAYBEL_8:def 5; end; Lm2: for L be lower-bounded LATTICE holds L is continuous implies ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving proof let L be lower-bounded LATTICE; assume A1: L is continuous; reconsider A = InclPoset Ids L as arithmetic lower-bounded LATTICE by WAYBEL13:14; take A; reconsider g = SupMap L as map of A,L; take g; the carrier of L c= rng g proof let y be set; assume y in the carrier of L; then reconsider y' = y as Element of L; downarrow y' is Element of A by YELLOW_2:43; then downarrow y' in the carrier of A & the carrier of L is non empty; then A2: downarrow y' in dom g by FUNCT_2:def 1; g.(downarrow y') = sup (downarrow y') by YELLOW_2:def 3 .= y' by WAYBEL_0:34; hence y in rng g by A2,FUNCT_1:def 5; end; then rng g = the carrier of L by XBOOLE_0:def 10; hence g is onto by FUNCT_2:def 3; thus g is infs-preserving by A1,WAYBEL13:33; g is sups-preserving by A1,WAYBEL13:33; then for X be Subset of A st X is non empty directed holds g preserves_sup_of X by WAYBEL_0:def 33; hence g is directed-sups-preserving by WAYBEL_0:def 37; end; theorem Th13: for L1,L2,L3 be non empty Poset for f be map of L1,L2 for g be map of L2,L3 st f is directed-sups-preserving & g is directed-sups-preserving holds g*f is directed-sups-preserving proof let L1,L2,L3 be non empty Poset; let f be map of L1,L2; let g be map of L2,L3; assume that A1: f is directed-sups-preserving and A2: g is directed-sups-preserving; now let X be Subset of L1; assume A3: X is non empty directed; then consider xx be set such that A4: xx in X by XBOOLE_0:def 1; dom f = the carrier of L1 by FUNCT_2:def 1; then A5: f.xx in f.:X by A4,FUNCT_1:def 12; for X1 be Ideal of L1 holds f preserves_sup_of X1 by A1,WAYBEL_0:def 37; then f is monotone by WAYBEL_0:72; then A6: f.:X is non empty directed by A3,A5,YELLOW_2:17; now assume A7: ex_sup_of X,L1; f preserves_sup_of X by A1,A3,WAYBEL_0:def 37; then A8: ex_sup_of f.:X,L2 & sup (f.: X) = f.sup X by A7,WAYBEL_0:def 31; g preserves_sup_of f.:X by A2,A6,WAYBEL_0:def 37; then A9: ex_sup_of g.:(f.:X),L3 & sup (g.:(f.:X)) = g.sup (f.:X) by A8,WAYBEL_0:def 31; hence ex_sup_of (g*f).:X,L3 by RELAT_1:159; sup X in the carrier of L1 & the carrier of L2 is non empty; then A10: sup X in dom f by FUNCT_2:def 1; thus sup ((g*f).:X) = g.(f.sup X) by A8,A9,RELAT_1:159 .= (g*f).sup X by A10,FUNCT_1:23; end; hence g*f preserves_sup_of X by WAYBEL_0:def 31; end; hence g*f is directed-sups-preserving by WAYBEL_0:def 37; end; begin :: Maps Preserving Sup's and Inf's theorem Th14: for L1,L2 be non empty RelStr for f be map of L1,L2 for X be Subset of Image f holds (inclusion f).:X = X proof let L1,L2 be non empty RelStr; let f be map of L1,L2; let X be Subset of Image f; thus (inclusion f).:X = (id Image f).:X by WAYBEL_1:def 17 .= X by Th3; end; theorem Th15: for X be set for c be map of BoolePoset X,BoolePoset X st c is idempotent directed-sups-preserving holds inclusion c is directed-sups-preserving proof let X be set; let c be map of BoolePoset X,BoolePoset X; assume A1: c is idempotent directed-sups-preserving; now let Y be Ideal of Image c; now assume ex_sup_of Y,Image c; A2: ex_sup_of Y,BoolePoset X by YELLOW_0:17; Y c= the carrier of Image c; then A3: Y c= rng c by YELLOW_2:11; reconsider Y' = Y as non empty directed Subset of BoolePoset X by YELLOW_2:7; A4: c preserves_sup_of Y' by A1,WAYBEL_0:def 37; "\/"(Y,BoolePoset X) in the carrier of BoolePoset X; then "\/"(Y,BoolePoset X) in dom c by FUNCT_2:def 1; then c.("\/"(Y,BoolePoset X)) in rng c by FUNCT_1:def 5; then "\/"(c.:Y,BoolePoset X) in rng c by A2,A4,WAYBEL_0:def 31; then "\/"(Y,BoolePoset X) in rng c by A1,A3,YELLOW_2:22; then "\/"(Y,BoolePoset X) in the carrier of Image c by YELLOW_2:11; then A5: "\/"(Y,BoolePoset X) is Element of Image c; thus ex_sup_of (inclusion c).:Y,BoolePoset X by YELLOW_0:17; thus sup ((inclusion c).:Y) = "\/"(Y,BoolePoset X) by Th14 .= sup Y by A2,A5,WAYBEL_8:19 .= (inclusion c).sup Y by WAYBEL_1:34; end; hence inclusion c preserves_sup_of Y by WAYBEL_0:def 31; end; hence inclusion c is directed-sups-preserving by WAYBEL_0:73; end; Lm3: for L be lower-bounded LATTICE holds (ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving) implies ex X be non empty set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic proof let L be lower-bounded LATTICE; given A be algebraic lower-bounded LATTICE, g be map of A,L such that A1: g is onto and A2: g is infs-preserving and A3: g is directed-sups-preserving; consider X be non empty set, c be closure map of BoolePoset X,BoolePoset X such that A4: c is directed-sups-preserving and A5: A,Image c are_isomorphic by WAYBEL13:35; consider f be map of A,Image c such that A6: f is isomorphic by A5,WAYBEL_1:def 8; A7: f is one-to-one by A6,WAYBEL_0:def 38; reconsider f1 = (f qua Function)" as map of Image c,A by A6,WAYBEL_0:67; A8: f1 is isomorphic by A6,WAYBEL_0:68; g has_a_lower_adjoint by A2,WAYBEL_1:17; then consider d be map of L,A such that A9: [g,d] is Galois by WAYBEL_1:def 11; g is monotone & d is monotone by A9,WAYBEL_1:9; then d*g is monotone by YELLOW_2:14; then reconsider k = d*g as kernel map of A,A by A9,WAYBEL_1:44; d is lower_adjoint by A9,WAYBEL_1:10; then d is sups-preserving by WAYBEL_1:14; then d is directed-sups-preserving by Lm1; then A10: k is directed-sups-preserving by A3,Th13; A11: f1*f = id dom f by A7,FUNCT_1:61 .= id (the carrier of A) by FUNCT_2:def 1 .= id A by GRCAT_1:def 11; reconsider p = (inclusion c)*f*k*f1*(corestr c) as map of BoolePoset X,BoolePoset X; A12: (inclusion c)*f*k*(f1*(id(Image c)))*(f*(k*(f1*(corestr c)))) = (inclusion c)*f*k*f1*(f*(k*(f1*(corestr c)))) by GRCAT_1:12 .= (inclusion c)*f*k*f1*f*(k*(f1*(corestr c))) by RELAT_1:55 .= (inclusion c)*f*k*(id A)*(k*(f1*(corestr c))) by A11,RELAT_1:55 .= (inclusion c)*f*k*(k*(f1*(corestr c))) by GRCAT_1:12 .= (inclusion c)*f*k*k*(f1*(corestr c)) by RELAT_1:55 .= (inclusion c)*f*(k*k)*(f1*(corestr c)) by RELAT_1:55 .= (inclusion c)*f*k*(f1*(corestr c)) by QUANTAL1:def 9 .= p by RELAT_1:55; p * p = (inclusion c)*f*k*f1*(corestr c)*((inclusion c)*f*k*(f1*(corestr c))) by RELAT_1:55 .= (inclusion c)*f*k*f1*(corestr c)* ((inclusion c)*f*(k*(f1*(corestr c)))) by RELAT_1:55 .= (inclusion c)*f*k*f1*(corestr c)*((inclusion c)* (f*(k*(f1*(corestr c))))) by RELAT_1:55 .= (inclusion c)*f*k*f1*(corestr c)*(inclusion c)* (f*(k*(f1*(corestr c)))) by RELAT_1:55 .= (inclusion c)*f*k*f1*((corestr c)*(inclusion c))* (f*(k*(f1*(corestr c)))) by RELAT_1:55 .= (inclusion c)*f*k*f1*(id(Image c))*(f*(k*(f1*(corestr c)))) by WAYBEL_1:36 .= p by A12,RELAT_1:55; then A13: p is idempotent by QUANTAL1:def 9; A14: f is monotone by A6,WAYBEL_0:def 38; A15: f1 is monotone by A8,WAYBEL_0:def 38; (inclusion c)*f is monotone by A14,YELLOW_2:14; then (inclusion c)*f*k is monotone by YELLOW_2:14; then (inclusion c)*f*k*f1 is monotone by A15,YELLOW_2:14; then p is monotone by YELLOW_2:14; then reconsider p as projection map of BoolePoset X,BoolePoset X by A13,WAYBEL_1:def 13; take X; take p; A16: inclusion c is directed-sups-preserving by A4,Th15; f is sups-preserving by A6,WAYBEL13:20; then A17: f is directed-sups-preserving by Lm1; f1 is sups-preserving by A8,WAYBEL13:20; then A18: f1 is directed-sups-preserving by Lm1; corestr c is sups-preserving by WAYBEL_1:58; then A19: corestr c is directed-sups-preserving by Lm1; (inclusion c)*f is directed-sups-preserving by A16,A17,Th13; then (inclusion c)*f*k is directed-sups-preserving by A10,Th13; then (inclusion c)*f*k*f1 is directed-sups-preserving by A18,Th13; hence p is directed-sups-preserving by A19,Th13; rng f1 = the carrier of A by A8,WAYBEL_0:66; then f1 is onto by FUNCT_2:def 3; then A20: g*f1 is onto by A1,Th2; then A21: g*f1*(corestr c) is onto by Th2; [f1,f] is Galois by A6,Th8; then [g*f1,f*d] is Galois by A9,Th7; then A22: L,Image(f*d) are_isomorphic by A20,Th6; A23: dom (f*d) = the carrier of L by FUNCT_2:def 1; A24: dom (inclusion(c)*f*d) = the carrier of L by FUNCT_2:def 1; now let x be set; assume A25: x in the carrier of L; then (f*d).x in the carrier of Image c by FUNCT_2:7; then (f*d).x is Element of Image c; hence (f*d).x = (inclusion(c)).((f*d).x) by WAYBEL_1:34 .= (inclusion(c)*(f*d)).x by A23,A25,FUNCT_1:23 .= (inclusion(c)*f*d).x by RELAT_1:55; end; then rng (f*d) = rng (inclusion(c)*f*d) by A23,A24,FUNCT_1:9; then A26: the carrier of (subrelstr rng (f*d)) = rng (inclusion(c)*f*d) by YELLOW_0:def 15; subrelstr rng (f*d) is full strict SubRelStr of BoolePoset X by Th1; then subrelstr rng (f*d) = subrelstr rng (inclusion(c)*f*d) by A26,YELLOW_0:def 15; then A27: subrelstr rng (f*d) = Image(inclusion(c)*f*d) by YELLOW_2:def 2; A28: rng(g*f1*(corestr c)) = the carrier of L by A21,FUNCT_2:def 3 .= dom(inclusion(c)*f*d) by FUNCT_2:def 1; p = inclusion(c)*f*d*g*f1*(corestr c) by RELAT_1:55 .= inclusion(c)*f*d*g*(f1*(corestr c)) by RELAT_1:55 .= inclusion(c)*f*d*(g*(f1*(corestr c))) by RELAT_1:55 .= inclusion(c)*f*d*(g*f1*(corestr c)) by RELAT_1:55; then rng(inclusion(c)*f*d) = rng p by A28,RELAT_1:47; then Image(inclusion(c)*f*d) = subrelstr rng p by YELLOW_2:def 2 .= Image p by YELLOW_2:def 2; hence L,Image p are_isomorphic by A22,A27,YELLOW_2:def 2; end; theorem Th16: :: THEOREM 2.10. for L be continuous complete LATTICE for p be kernel map of L,L st p is directed-sups-preserving holds Image p is continuous LATTICE proof let L be continuous complete LATTICE; let p be kernel map of L,L such that A1: p is directed-sups-preserving; A2: corestr(p) is infs-preserving by WAYBEL_1:59; now let X be Subset of L; assume X is non empty directed; then A3: p preserves_sup_of X by A1,WAYBEL_0:def 37; A4: Image p is sups-inheriting by WAYBEL_1:56; now assume A5: ex_sup_of X,L; Image p is complete by WAYBEL_1:57; hence ex_sup_of (corestr(p)).:X,Image p by YELLOW_0:17; A6: (corestr(p)).:X = p.:X by WAYBEL_1:32; ex_sup_of (p).:X,L by YELLOW_0:17; then "\/"((corestr p).:X,L) in the carrier of Image p by A4,A6,YELLOW_0:def 19; hence sup ((corestr(p)).:X) = sup (p.:X) by A6,YELLOW_0:69 .= p.sup X by A3,A5,WAYBEL_0:def 31 .= (corestr(p)).sup X by WAYBEL_1:32; end; hence corestr(p) preserves_sup_of X by WAYBEL_0:def 31; end; then corestr(p) is directed-sups-preserving by WAYBEL_0:def 37; hence Image p is continuous LATTICE by A2,WAYBEL_5:33; end; theorem Th17: :: THEOREM 2.14. for L be continuous complete LATTICE for p be projection map of L,L st p is directed-sups-preserving holds Image p is continuous LATTICE proof let L be continuous complete LATTICE; let p be projection map of L,L such that A1: p is directed-sups-preserving; reconsider Lk = {k where k is Element of L: p.k <= k} as non empty Subset of L by WAYBEL_1:46; A2: subrelstr Lk is infs-inheriting by WAYBEL_1:53; subrelstr Lk is directed-sups-inheriting by A1,WAYBEL_1:55; then A3: subrelstr Lk is continuous LATTICE by A2,WAYBEL_5:28; A4: subrelstr Lk is complete by A2,YELLOW_2:32; reconsider pk = p|Lk as map of subrelstr Lk, subrelstr Lk by WAYBEL_1:49; A5: pk is kernel by WAYBEL_1:51; A6: subrelstr rng pk is full SubRelStr of L by Th1; A7: the carrier of subrelstr rng p = rng p by YELLOW_0:def 15 .= rng pk by WAYBEL_1:47 .= the carrier of subrelstr rng pk by YELLOW_0:def 15; A8: Image p = subrelstr rng p by YELLOW_2:def 2 .= subrelstr rng pk by A6,A7,YELLOW_0:58 .= Image pk by YELLOW_2:def 2; now let X be Subset of subrelstr Lk; assume A9: X is non empty directed; reconsider X' = X as Subset of L by WAYBEL13:3; reconsider X' as non empty directed Subset of L by A9,YELLOW_2:7; A10: p preserves_sup_of X' by A1,WAYBEL_0:def 37; now assume ex_sup_of X,subrelstr Lk; subrelstr Lk is infs-inheriting by WAYBEL_1:53; then subrelstr Lk is complete LATTICE by YELLOW_2:32; hence ex_sup_of pk.:X,subrelstr Lk by YELLOW_0:17; A11: dom pk = the carrier of subrelstr Lk by FUNCT_2:def 1; A12: ex_sup_of X,L by YELLOW_0:17; A13: ex_sup_of p.:X,L by YELLOW_0:17; pk is projection by A5,WAYBEL_1:def 15; then pk is monotone by WAYBEL_1:def 13; then A14: pk.:X is directed Subset of subrelstr Lk by A9,YELLOW_2:17; for Y be non empty Subset of subrelstr Lk holds pk.:Y is non empty; then A15: pk.:X <> {} by A9; A16: subrelstr Lk is directed-sups-inheriting by A1,WAYBEL_1:55; then A17: sup X' = sup X by A9,A12,WAYBEL_0:7; X c= the carrier of subrelstr Lk; then X c= Lk by YELLOW_0:def 15; then pk.:X = p.:X by EXTENS_1:1; hence sup (pk.:X) = sup (p.:X) by A13,A14,A15,A16,WAYBEL_0:7 .= p.sup X' by A10,A12,WAYBEL_0:def 31 .= pk.sup X by A11,A17,FUNCT_1:70; end; hence pk preserves_sup_of X by WAYBEL_0:def 31; end; then pk is directed-sups-preserving by WAYBEL_0:def 37; hence Image p is continuous LATTICE by A3,A4,A5,A8,Th16; end; Lm4: for L be LATTICE holds (ex X be set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic) implies L is continuous proof let L be LATTICE; given X be set, p be projection map of BoolePoset X,BoolePoset X such that A1: p is directed-sups-preserving and A2: L,Image p are_isomorphic; A3: Image p,L are_isomorphic by A2,WAYBEL_1:7; Image p is continuous by A1,Th17; hence L is continuous by A3,Th11; end; theorem :: THEOREM 4.16. (1) iff (2) for L be lower-bounded LATTICE holds L is continuous iff ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving proof let L be lower-bounded LATTICE; thus L is continuous implies ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving by Lm2; thus (ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving) implies L is continuous proof assume ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving; then ex X be non empty set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic by Lm3; hence L is continuous by Lm4; end; end; theorem :: THEOREM 4.16. (1) iff (3) for L be lower-bounded LATTICE holds L is continuous iff ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving proof let L be lower-bounded LATTICE; thus L is continuous implies ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving proof assume L is continuous; then ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving by Lm2; hence ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving; end; thus (ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving) implies L is continuous proof assume ex A be algebraic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving; then ex X be non empty set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic by Lm3; hence L is continuous by Lm4; end; end; theorem :: THEOREM 4.16. (1) iff (4) for L be lower-bounded LATTICE holds ( L is continuous implies ex X be non empty set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic ) & (( ex X be set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic ) implies L is continuous ) proof let L be lower-bounded LATTICE; thus L is continuous implies ex X be non empty set, p be projection map of BoolePoset X,BoolePoset X st p is directed-sups-preserving & L,Image p are_isomorphic proof assume L is continuous; then ex A be arithmetic lower-bounded LATTICE, g be map of A,L st g is onto & g is infs-preserving & g is directed-sups-preserving by Lm2; hence thesis by Lm3; end; thus thesis by Lm4; end; begin :: Atoms Elements theorem for L be non empty RelStr for x be Element of L holds x in PRIME (L opp) iff x is co-prime proof let L be non empty RelStr; let x be Element of L; hereby assume x in PRIME (L opp); then x~ in PRIME (L opp) by LATTICE3:def 6; then x~ is prime by WAYBEL_6:def 7; hence x is co-prime by WAYBEL_6:def 8; end; assume x is co-prime; then x~ is prime by WAYBEL_6:def 8; then x~ in PRIME (L opp) by WAYBEL_6:def 7; hence x in PRIME (L opp) by LATTICE3:def 6; end; definition let L be non empty RelStr; let a be Element of L; attr a is atom means :Def1: Bottom L < a & for b be Element of L st Bottom L < b & b <= a holds b = a; end; definition let L be non empty RelStr; func ATOM L -> Subset of L means :Def2: for x be Element of L holds x in it iff x is atom; existence proof defpred P[Element of L] means $1 is atom; consider X be Subset of L such that A1: for x be Element of L holds x in X iff P[x] from SSubsetEx; take X; thus thesis by A1; end; uniqueness proof let A1,A2 be Subset of L such that A2: for x be Element of L holds x in A1 iff x is atom and A3: for x be Element of L holds x in A2 iff x is atom; now let x be set; thus x in A1 implies x in A2 proof assume A4: x in A1; then reconsider x' = x as Element of L; x' is atom by A2,A4; hence x in A2 by A3; end; thus x in A2 implies x in A1 proof assume A5: x in A2; then reconsider x' = x as Element of L; x' is atom by A3,A5; hence x in A1 by A2; end; end; hence A1 = A2 by TARSKI:2; end; end; canceled; theorem Th23: for L be Boolean LATTICE for a be Element of L holds a is atom iff a is co-prime & a <> Bottom L proof let L be Boolean LATTICE; let a be Element of L; thus a is atom implies a is co-prime & a <> Bottom L proof assume A1: a is atom; now let x,y be Element of L; assume that A2: a <= x "\/" y and A3: not a <= x; A4: a "/\" x <> a by A3,YELLOW_0:25; a "/\" x <= a by YELLOW_0:23; then not Bottom L < a "/\" x by A1,A4,Def1; then A5: (not Bottom L <= a "/\" x) or (not Bottom L <> a "/\" x) by ORDERS_1:def 10; a = a "/\" (x "\/" y) by A2,YELLOW_0:25 .= (a "/\" x) "\/" (a "/\" y) by WAYBEL_1:def 3 .= a "/\" y by A5,WAYBEL_1:4,YELLOW_0:44; hence a <= y by YELLOW_0:25; end; hence a is co-prime by WAYBEL14:14; thus a <> Bottom L by A1,Def1; end; assume that A6: a is co-prime and A7: a <> Bottom L; Bottom L <= a by YELLOW_0:44; then A8: Bottom L < a by A7,ORDERS_1:def 10; now let b be Element of L; assume that A9: Bottom L < b and A10: b <= a; consider c be Element of L such that A11: c is_a_complement_of b by WAYBEL_1:def 24; A12: b "\/" c = Top L & b "/\" c = Bottom L by A11,WAYBEL_1:def 23; then A13: a <= b "\/" c by YELLOW_0:45; not a <= c proof assume a <= c; then b <= c by A10,ORDERS_1:26; hence contradiction by A9,A12,YELLOW_0:25; end; then a <= b by A6,A13,WAYBEL14:14; hence b = a by A10,ORDERS_1:25; end; hence a is atom by A8,Def1; end; definition let L be Boolean LATTICE; cluster atom -> co-prime Element of L; coherence by Th23; end; theorem for L be Boolean LATTICE holds ATOM L = (PRIME (L opp)) \ {Bottom L} proof let L be Boolean LATTICE; A1: ATOM L c= (PRIME (L opp)) \ {Bottom L} proof let x be set; assume A2: x in ATOM L; then reconsider x' = x as Element of L; A3: x' is atom by A2,Def2; then x' is co-prime by Th23; then x'~ is prime by WAYBEL_6:def 8; then x'~ in PRIME (L opp) by WAYBEL_6:def 7; then A4: x in PRIME (L opp) by LATTICE3:def 6; x <> Bottom L by A3,Th23; then not x in {Bottom L} by TARSKI:def 1; hence x in (PRIME (L opp)) \ {Bottom L} by A4,XBOOLE_0:def 4; end; (PRIME (L opp)) \ {Bottom L} c= ATOM L proof let x be set; assume x in (PRIME (L opp)) \ {Bottom L}; then A5: x in PRIME (L opp) & not x in {Bottom L} by XBOOLE_0:def 4; then reconsider x' = x as Element of (L opp); x' <> Bottom L by A5,TARSKI:def 1; then A6: ~x' <> Bottom L by LATTICE3:def 7; A7: x' is prime by A5,WAYBEL_6:def 7; (~x')~ = ~x' by LATTICE3:def 6 .= x' by LATTICE3:def 7; then ~x' is co-prime by A7,WAYBEL_6:def 8; then ~x' is atom by A6,Th23; then ~x' in ATOM L by Def2; hence x in ATOM L by LATTICE3:def 7; end; hence thesis by A1,XBOOLE_0:def 10; end; theorem for L be Boolean LATTICE for x,a be Element of L st a is atom holds a <= x iff not a <= 'not' x proof let L be Boolean LATTICE; let x,a be Element of L; assume A1: a is atom; thus a <= x implies not a <= 'not' x proof assume that A2: a <= x and A3: a <= 'not' x; a = a "\/" Bottom L by WAYBEL_1:4 .= a "\/" (x "/\" 'not' x) by YELLOW_5:37 .= (a "\/" x) "/\" ('not' x "\/" a) by WAYBEL_1:6 .= x "/\" ('not' x "\/" a) by A2,YELLOW_0:24 .= x "/\" 'not' x by A3,YELLOW_0:24 .= Bottom L by YELLOW_5:37; hence contradiction by A1,Th23; end; thus not a <= 'not' x implies a <= x proof assume that A4: not a <= 'not' x and A5: not a <= x; A6: a is co-prime by A1,Th23; a <= Top L by YELLOW_0:45; then a <= (x "\/" 'not' x) by YELLOW_5:37; hence contradiction by A4,A5,A6,WAYBEL14:14; end; end; theorem Th26: for L be complete Boolean LATTICE for X be Subset of L for x be Element of L holds x "/\" sup X = "\/"({x"/\"y where y is Element of L: y in X},L) proof let L be complete Boolean LATTICE; let X be Subset of L; let x be Element of L; for y be Element of L holds y "/\" has_an_upper_adjoint by WAYBEL_1:def 19; hence x "/\" sup X = "\/"({x"/\"y where y is Element of L: y in X},L) by WAYBEL_1:67; end; theorem Th27: for L be lower-bounded with_infima antisymmetric non empty RelStr for x,y be Element of L st x is atom & y is atom & x <> y holds x "/\" y = Bottom L proof let L be lower-bounded with_infima antisymmetric non empty RelStr; let x,y be Element of L; assume that A1: x is atom and A2: y is atom and A3: x <> y and A4: x "/\" y <> Bottom L; Bottom L <= x "/\" y by YELLOW_0:44; then A5: Bottom L < x "/\" y by A4,ORDERS_1:def 10; A6: x "/\" y <= x & x "/\" y <= y by YELLOW_0:23; then x = x "/\" y by A1,A5,Def1 .= y by A2,A5,A6,Def1; hence contradiction by A3; end; theorem Th28: for L be complete Boolean LATTICE for x be Element of L for A be Subset of L st A c= ATOM L holds x in A iff x is atom & x <= sup A proof let L be complete Boolean LATTICE; let x be Element of L; let A be Subset of L; assume A1: A c= ATOM L; thus x in A implies x is atom & x <= sup A proof assume A2: x in A; hence x is atom by A1,Def2; sup A is_>=_than A by YELLOW_0:32; hence x <= sup A by A2,LATTICE3:def 9; end; thus x is atom & x <= sup A implies x in A proof assume that A3: x is atom and A4: x <= sup A and A5: not x in A; now let b be Element of L; assume b in { x "/\" y where y is Element of L: y in A }; then consider y be Element of L such that A6: b = x "/\" y and A7: y in A; y is atom by A1,A7,Def2; hence b <= Bottom L by A3,A5,A6,A7,Th27; end; then A8: Bottom L is_>=_than { x "/\" y where y is Element of L: y in A } by LATTICE3:def 9; x = x "/\" sup A by A4,YELLOW_0:25 .= "\/"({ x "/\" y where y is Element of L: y in A },L) by Th26; then x <= Bottom L by A8,YELLOW_0:32; then x = Bottom L by YELLOW_5:22; hence contradiction by A3,Th23; end; end; theorem Th29: for L be complete Boolean LATTICE for X,Y be Subset of L st X c= ATOM L & Y c= ATOM L holds X c= Y iff sup X <= sup Y proof let L be complete Boolean LATTICE; let X,Y be Subset of L; assume that A1: X c= ATOM L and A2: Y c= ATOM L; thus X c= Y implies sup X <= sup Y proof assume A3: X c= Y; ex_sup_of X,L & ex_sup_of Y,L by YELLOW_0:17; hence sup X <= sup Y by A3,YELLOW_0:34; end; thus sup X <= sup Y implies X c= Y proof assume A4: sup X <= sup Y; thus X c= Y proof let z be set; assume A5: z in X; then reconsider z1 = z as Element of L; A6: z1 is atom by A1,A5,Def2; sup X is_>=_than X by YELLOW_0:32; then z1 <= sup X by A5,LATTICE3:def 9; then z1 <= sup Y by A4,ORDERS_1:26; hence z in Y by A2,A6,Th28; end; end; end; Lm5: :: (1) => (2) for L be Boolean LATTICE holds ( ex X be set st L,BoolePoset X are_isomorphic ) implies L is arithmetic proof let L be Boolean LATTICE; given X be set such that A1: L,BoolePoset X are_isomorphic; BoolePoset X,L are_isomorphic by A1,WAYBEL_1:7; hence L is arithmetic by Th12; end; Lm6: :: (4) => (5) for L be Boolean LATTICE holds L is continuous implies L opp is continuous proof let L be Boolean LATTICE; assume A1: L is continuous; L , L opp are_isomorphic by YELLOW_7:38; hence L opp is continuous by A1,Th11; end; Lm7: :: (5) <=> (6) for L be Boolean LATTICE holds ( L is continuous & L opp is continuous ) iff L is completely-distributive proof let L be Boolean LATTICE; thus ( L is continuous & L opp is continuous ) implies L is completely-distributive proof assume that A1: L is continuous and A2: L opp is continuous; L is continuous LATTICE by A1; then L is up-complete lower-bounded LATTICE; hence thesis by A1,A2,WAYBEL_6:39; end; thus L is completely-distributive implies ( L is continuous & L opp is continuous ) proof assume L is completely-distributive; then L is completely-distributive LATTICE; hence thesis by WAYBEL_6:39; end; end; Lm8: :: (6) => (7) for L be Boolean LATTICE holds L is completely-distributive implies ( L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X ) proof let L be Boolean LATTICE; assume L is completely-distributive; then A1: L is completely-distributive LATTICE; hence L is complete; let x be Element of L; consider X1 be Subset of L such that A2: x = sup X1 and A3: for y be Element of L st y in X1 holds y is co-prime by A1,WAYBEL_6:38; reconsider X = X1 \ {Bottom L} as Subset of L; take X; thus X c= ATOM L proof let z be set; assume A4: z in X; then A5: z in X1 & not z in {Bottom L} by XBOOLE_0:def 4; reconsider z' = z as Element of L by A4; A6: z' <> Bottom L by A5,TARSKI:def 1; z' is co-prime by A3,A5; then z' is atom by A6,Th23; hence z in ATOM L by Def2; end; A7: x is_>=_than X1 & for b be Element of L st b is_>=_than X1 holds x <= b by A1,A2,YELLOW_0:32; now let c be Element of L; assume c in X; then c in X1 by XBOOLE_0:def 4; hence c <= x by A7,LATTICE3:def 9; end; then A8: x is_>=_than X by LATTICE3:def 9; now let b be Element of L; assume A9: b is_>=_than X; now let c be Element of L; assume A10: c in X1; now per cases; suppose c <> Bottom L; then not c in {Bottom L} by TARSKI:def 1; then c in X by A10,XBOOLE_0:def 4; hence c <= b by A9,LATTICE3:def 9; suppose c = Bottom L; hence c <= b by YELLOW_0:44; end; hence c <= b; end; then b is_>=_than X1 by LATTICE3:def 9; hence x <= b by A1,A2,YELLOW_0:32; end; hence x = sup X by A1,A8,YELLOW_0:32; end; Lm9: :: (7) => (1) for L be Boolean LATTICE holds ( L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X ) implies ex Y be set st L,BoolePoset Y are_isomorphic proof let L be Boolean LATTICE; assume that A1: L is complete and A2: for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X; take Y = ATOM L; defpred P[set,set] means ex x' be Subset of L st x' = $1 & $2 = sup x'; A3: for x be Element of BoolePoset Y ex y be Element of L st P[x, y] proof let x be Element of BoolePoset Y; x c= Y by WAYBEL_8:28; then x c= the carrier of L by XBOOLE_1:1; then reconsider x' = x as Subset of L; take y = sup x'; take x'; thus x' = x & y = sup x'; end; consider f be map of BoolePoset Y,L such that A4: for x be Element of BoolePoset Y holds P[x, f.x] from NonUniqExMD(A3); now let z,v be Element of BoolePoset Y; consider z' be Subset of L such that A5: z' = z and A6: f.z = sup z' by A4; consider v' be Subset of L such that A7: v' = v and A8: f.v = sup v' by A4; A9: z' c= ATOM L by A5,WAYBEL_8:28; A10: v' c= ATOM L by A7,WAYBEL_8:28; assume f.z = f.v; then z c= v & v c= z by A1,A5,A6,A7,A8,A9,A10,Th29; hence z = v by XBOOLE_0:def 10; end; then A11: f is one-to-one by WAYBEL_1:def 1; the carrier of L c= rng f proof let k be set; assume k in the carrier of L; then k is Element of L; then consider K be Subset of L such that A12: K c= ATOM L and A13: k = sup K by A2; A14: K is Element of BoolePoset Y by A12,WAYBEL_8:28; then K in the carrier of BoolePoset Y & the carrier of L is non empty; then A15: K in dom f by FUNCT_2:def 1; consider K' be Subset of L such that A16: K' = K and A17: f.K = sup K' by A4,A14; thus k in rng f by A13,A15,A16,A17,FUNCT_1:def 5; end; then A18: rng f = the carrier of L by XBOOLE_0:def 10; now let z,v be Element of BoolePoset Y; consider z' be Subset of L such that A19: z' = z and A20: f.z = sup z' by A4; consider v' be Subset of L such that A21: v' = v and A22: f.v = sup v' by A4; A23: ex_sup_of z',L by A1,YELLOW_0:17; A24: ex_sup_of v',L by A1,YELLOW_0:17; A25: z' c= ATOM L by A19,WAYBEL_8:28; A26: v' c= ATOM L by A21,WAYBEL_8:28; thus z <= v implies f.z <= f.v proof assume z <= v; then z c= v by YELLOW_1:2; hence f.z <= f.v by A19,A20,A21,A22,A23,A24,YELLOW_0:34; end; thus f.z <= f.v implies z <= v proof assume f.z <= f.v; then z c= v by A1,A19,A20,A21,A22,A25,A26,Th29; hence z <= v by YELLOW_1:2; end; end; then f is isomorphic by A11,A18,WAYBEL_0:66; then BoolePoset Y,L are_isomorphic by WAYBEL_1:def 8; hence L,BoolePoset Y are_isomorphic by WAYBEL_1:7; end; begin :: More on the Boolean Lattice theorem :: THEOREM 4.18. (2) iff (1) for L be Boolean LATTICE holds L is arithmetic iff ex X be set st L,BoolePoset X are_isomorphic proof let L be Boolean LATTICE; hereby assume L is arithmetic; then L is algebraic by WAYBEL_8:def 5; then L is continuous by WAYBEL_8:7; then L is continuous & L opp is continuous by Lm6; then L is completely-distributive by Lm7; then L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; hence ex X be set st L,BoolePoset X are_isomorphic by Lm9; end; thus thesis by Lm5; end; theorem :: THEOREM 4.18. (2) iff (3) for L be Boolean LATTICE holds L is arithmetic iff L is algebraic proof let L be Boolean LATTICE; thus L is arithmetic implies L is algebraic by WAYBEL_8:def 5; assume L is algebraic; then L is continuous by WAYBEL_8:7; then L is continuous & L opp is continuous by Lm6; then L is completely-distributive by Lm7; then L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; then ex X be set st L,BoolePoset X are_isomorphic by Lm9; hence L is arithmetic by Lm5; end; theorem :: THEOREM 4.18. (2) iff (4) for L be Boolean LATTICE holds L is arithmetic iff L is continuous proof let L be Boolean LATTICE; thus L is arithmetic implies L is continuous proof assume L is arithmetic; then L is algebraic by WAYBEL_8:def 5; hence L is continuous by WAYBEL_8:7; end; assume L is continuous; then L is continuous & L opp is continuous by Lm6; then L is completely-distributive by Lm7; then L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; then ex X be set st L,BoolePoset X are_isomorphic by Lm9; hence L is arithmetic by Lm5; end; theorem :: THEOREM 4.18. (2) iff (5) for L be Boolean LATTICE holds L is arithmetic iff (L is continuous & L opp is continuous) proof let L be Boolean LATTICE; thus L is arithmetic implies (L is continuous & L opp is continuous) proof assume L is arithmetic; then L is algebraic by WAYBEL_8:def 5; then L is continuous by WAYBEL_8:7; hence L is continuous & L opp is continuous by Lm6; end; assume L is continuous & L opp is continuous; then L is completely-distributive by Lm7; then L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; then ex X be set st L,BoolePoset X are_isomorphic by Lm9; hence L is arithmetic by Lm5; end; theorem :: THEOREM 4.18. (2) iff (6) for L be Boolean LATTICE holds L is arithmetic iff L is completely-distributive proof let L be Boolean LATTICE; thus L is arithmetic implies L is completely-distributive proof assume L is arithmetic; then L is algebraic by WAYBEL_8:def 5; then L is continuous by WAYBEL_8:7; then L is continuous & L opp is continuous by Lm6; hence L is completely-distributive by Lm7; end; assume L is completely-distributive; then L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; then ex X be set st L,BoolePoset X are_isomorphic by Lm9; hence L is arithmetic by Lm5; end; theorem :: THEOREM 4.18. (2) iff (7) for L be Boolean LATTICE holds L is arithmetic iff ( L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X ) proof let L be Boolean LATTICE; hereby assume L is arithmetic; then L is algebraic by WAYBEL_8:def 5; then L is continuous by WAYBEL_8:7; then L is continuous & L opp is continuous by Lm6; then L is completely-distributive by Lm7; hence L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X by Lm8; end; assume L is complete & for x be Element of L ex X be Subset of L st X c= ATOM L & x = sup X; then ex X be set st L,BoolePoset X are_isomorphic by Lm9; hence L is arithmetic by Lm5; end;