let M be non empty Reflexive symmetric triangle MetrStruct ; :: thesis: ( M is complete implies for a being Point of M st ex b being Point of M st dist (a,b) <> 0 holds
for X being infinite set holds
( WellSpace (a,X) is complete & ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty ) ) )

assume A1: M is complete ; :: thesis: for a being Point of M st ex b being Point of M st dist (a,b) <> 0 holds
for X being infinite set holds
( WellSpace (a,X) is complete & ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty ) )

let a be Point of M; :: thesis: ( ex b being Point of M st dist (a,b) <> 0 implies for X being infinite set holds
( WellSpace (a,X) is complete & ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty ) ) )

assume ex b being Point of M st dist (a,b) <> 0 ; :: thesis: for X being infinite set holds
( WellSpace (a,X) is complete & ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty ) )

then consider b being Point of M such that
A2: dist (a,b) <> 0 ;
let X be infinite set ; :: thesis: ( WellSpace (a,X) is complete & ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty ) )

set W = WellSpace (a,X);
thus WellSpace (a,X) is complete by A1, Th41; :: thesis: ex S being non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) st
( S is closed & S is non-ascending & meet S is empty )

set TW = TopSpaceMetr (WellSpace (a,X));
consider f being sequence of X such that
A3: f is one-to-one by DICKSON:3;
defpred S1[ object , object ] means $2 = [(f . $1),b];
A4: b <> a by A2, METRIC_1:1;
A5: for x being object st x in NAT holds
ex y being object st
( y in the carrier of (TopSpaceMetr (WellSpace (a,X))) & S1[x,y] )
proof
let x be object ; :: thesis: ( x in NAT implies ex y being object st
( y in the carrier of (TopSpaceMetr (WellSpace (a,X))) & S1[x,y] ) )

assume x in NAT ; :: thesis: ex y being object st
( y in the carrier of (TopSpaceMetr (WellSpace (a,X))) & S1[x,y] )

then x in dom f by FUNCT_2:def 1;
then A6: f . x in rng f by FUNCT_1:def 3;
take [(f . x),b] ; :: thesis: ( [(f . x),b] in the carrier of (TopSpaceMetr (WellSpace (a,X))) & S1[x,[(f . x),b]] )
thus ( [(f . x),b] in the carrier of (TopSpaceMetr (WellSpace (a,X))) & S1[x,[(f . x),b]] ) by A4, A6, Th37; :: thesis: verum
end;
consider s being sequence of the carrier of (TopSpaceMetr (WellSpace (a,X))) such that
A7: for x being object st x in NAT holds
S1[x,s . x] from FUNCT_2:sch 1(A5);
deffunc H1( object ) -> set = {(s . $1)};
A8: for x being object st x in NAT holds
H1(x) in bool the carrier of (TopSpaceMetr (WellSpace (a,X)))
proof
A9: dom s = NAT by FUNCT_2:def 1;
let x be object ; :: thesis: ( x in NAT implies H1(x) in bool the carrier of (TopSpaceMetr (WellSpace (a,X))) )
assume x in NAT ; :: thesis: H1(x) in bool the carrier of (TopSpaceMetr (WellSpace (a,X)))
then s . x in rng s by A9, FUNCT_1:def 3;
then H1(x) is Subset of (WellSpace (a,X)) by SUBSET_1:33;
hence H1(x) in bool the carrier of (TopSpaceMetr (WellSpace (a,X))) ; :: thesis: verum
end;
consider S being SetSequence of (TopSpaceMetr (WellSpace (a,X))) such that
A10: for x being object st x in NAT holds
S . x = H1(x) from FUNCT_2:sch 2(A8);
A11: now :: thesis: for x1, x2 being object st x1 in NAT & x2 in NAT & S . x1 = S . x2 holds
x1 = x2
let x1, x2 be object ; :: thesis: ( x1 in NAT & x2 in NAT & S . x1 = S . x2 implies x1 = x2 )
assume that
A12: x1 in NAT and
A13: x2 in NAT and
A14: S . x1 = S . x2 ; :: thesis: x1 = x2
A15: S . x2 = {(s . x2)} by A10, A13;
A16: s . x1 = [(f . x1),b] by A7, A12;
A17: s . x1 in {(s . x1)} by TARSKI:def 1;
A18: s . x2 = [(f . x2),b] by A7, A13;
S . x1 = {(s . x1)} by A10, A12;
then s . x1 = s . x2 by A14, A15, A17, TARSKI:def 1;
then f . x1 = f . x2 by A16, A18, XTUPLE_0:1;
hence x1 = x2 by A3, A12, A13, FUNCT_2:19; :: thesis: verum
end;
reconsider rngs = rng s as Subset of (TopSpaceMetr (WellSpace (a,X))) ;
set F = { {x} where x is Element of (TopSpaceMetr (WellSpace (a,X))) : x in rngs } ;
reconsider F = { {x} where x is Element of (TopSpaceMetr (WellSpace (a,X))) : x in rngs } as Subset-Family of (TopSpaceMetr (WellSpace (a,X))) by RELSET_2:16;
dist (a,b) > 0 by A2, METRIC_1:5;
then A19: 2 * (dist (a,b)) > 0 by XREAL_1:129;
A20: rng S c= F
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in rng S or x in F )
assume x in rng S ; :: thesis: x in F
then consider y being object such that
A21: y in dom S and
A22: S . y = x by FUNCT_1:def 3;
dom s = NAT by FUNCT_2:def 1;
then A23: s . y in rngs by A21, FUNCT_1:def 3;
x = {(s . y)} by A10, A21, A22;
hence x in F by A23; :: thesis: verum
end;
now :: thesis: for x being object st x in dom S holds
not S . x is empty
let x be object ; :: thesis: ( x in dom S implies not S . x is empty )
assume x in dom S ; :: thesis: not S . x is empty
then S . x = {(s . x)} by A10;
hence not S . x is empty ; :: thesis: verum
end;
then S is non-empty by FUNCT_1:def 9;
then consider R being non-empty closed SetSequence of (TopSpaceMetr (WellSpace (a,X))) such that
A24: R is non-ascending and
A25: ( F is locally_finite & S is one-to-one implies meet R = {} ) and
A26: for i being Nat ex Si being Subset-Family of (TopSpaceMetr (WellSpace (a,X))) st
( R . i = Cl (union Si) & Si = { (S . j) where j is Element of NAT : j >= i } ) by A20, Th23;
reconsider R9 = R as non-empty SetSequence of (WellSpace (a,X)) ;
A27: now :: thesis: for x, y being Point of (WellSpace (a,X)) st x in rngs & y in rngs & x <> y holds
dist (x,y) = 2 * (dist (a,b))
let x, y be Point of (WellSpace (a,X)); :: thesis: ( x in rngs & y in rngs & x <> y implies dist (x,y) = 2 * (dist (a,b)) )
assume that
A28: x in rngs and
A29: y in rngs and
A30: x <> y ; :: thesis: dist (x,y) = 2 * (dist (a,b))
consider y1 being object such that
A31: y1 in dom s and
A32: s . y1 = y by A29, FUNCT_1:def 3;
A33: y = [(f . y1),b] by A7, A31, A32;
consider x1 being object such that
A34: x1 in dom s and
A35: s . x1 = x by A28, FUNCT_1:def 3;
x = [(f . x1),b] by A7, A34, A35;
then (well_dist (a,X)) . (x,y) = (dist (b,a)) + (dist (a,b)) by A30, A33, Def10;
hence dist (x,y) = 2 * (dist (a,b)) ; :: thesis: verum
end;
now :: thesis: for i being Nat holds R9 . i is bounded
let i be Nat; :: thesis: R9 . i is bounded
consider Si being Subset-Family of (TopSpaceMetr (WellSpace (a,X))) such that
A36: R . i = Cl (union Si) and
A37: Si = { (S . j) where j is Element of NAT : j >= i } by A26;
reconsider SI = union Si as Subset of (WellSpace (a,X)) ;
now :: thesis: for x, y being Point of (WellSpace (a,X)) st x in SI & y in SI holds
dist (x,y) <= 2 * (dist (a,b))
let x, y be Point of (WellSpace (a,X)); :: thesis: ( x in SI & y in SI implies dist (x,y) <= 2 * (dist (a,b)) )
assume that
A38: x in SI and
A39: y in SI ; :: thesis: dist (x,y) <= 2 * (dist (a,b))
consider xS being set such that
A40: x in xS and
A41: xS in Si by A38, TARSKI:def 4;
consider j1 being Element of NAT such that
A42: xS = S . j1 and
j1 >= i by A37, A41;
A43: S . j1 = {(s . j1)} by A10;
A44: dom s = NAT by FUNCT_2:def 1;
then s . j1 in rngs by FUNCT_1:def 3;
then A45: x in rngs by A40, A42, A43, TARSKI:def 1;
consider yS being set such that
A46: y in yS and
A47: yS in Si by A39, TARSKI:def 4;
consider j2 being Element of NAT such that
A48: yS = S . j2 and
j2 >= i by A37, A47;
A49: S . j2 = {(s . j2)} by A10;
s . j2 in rngs by A44, FUNCT_1:def 3;
then A50: y in rngs by A46, A48, A49, TARSKI:def 1;
( x = y or x <> y ) ;
hence dist (x,y) <= 2 * (dist (a,b)) by A19, A27, A45, A50, METRIC_1:1; :: thesis: verum
end;
then SI is bounded by A19;
hence R9 . i is bounded by A36, Th8; :: thesis: verum
end;
then reconsider R9 = R9 as non-empty pointwise_bounded SetSequence of (WellSpace (a,X)) by Def1;
take R9 ; :: thesis: ( R9 is closed & R9 is non-ascending & meet R9 is empty )
thus ( R9 is closed & R9 is non-ascending ) by A24, Th7; :: thesis: meet R9 is empty
for x, y being Point of (WellSpace (a,X)) st x <> y & x in rngs & y in rngs holds
dist (x,y) >= 2 * (dist (a,b)) by A27;
hence meet R9 is empty by A25, A19, A11, Lm7, FUNCT_2:19; :: thesis: verum