reconsider B1 = product b1 as Segre-Coset of A by A2;
set s = permutation_of_indices f;
set i = indx b1;
defpred S1[ set , set ] means for J being ManySortedSet of I st J in f .: (product (b1 +* ((indx b1),{$1}))) holds
$2 = J . ((permutation_of_indices f) . (indx b1));
set B = the carrier of (A . (indx b1));
set t = permutation_of_indices f;
reconsider B2 = f .: B1 as Segre-Coset of A by A1, PENCIL_2:24;
consider b2 being non trivial-yielding Segre-like ManySortedSubset of Carrier A such that
A3: product b2 = B2 and
A4: b2 . (indx b2) = [#] (A . (indx b2)) by PENCIL_2:def 2;
set j = indx b2;
A5: f is bijective by PENCIL_2:def 4;
then A6: f " B2 c= B1 by FUNCT_1:82;
A7: Segre_Product A = TopStruct(# (product (Carrier A)),(Segre_Blocks A) #) by PENCIL_1:def 23;
A8: for x being set st x in the carrier of (A . (indx b1)) holds
ex y being set st S1[x,y]
proof
let x be set ; :: thesis: ( x in the carrier of (A . (indx b1)) implies ex y being set st S1[x,y] )
consider bb being set such that
A9: bb in B1 by XBOOLE_0:def 1;
A10: ex bf being Function st
( bf = bb & dom bf = dom b1 & ( for o being set st o in dom b1 holds
bf . o in b1 . o ) ) by A9, CARD_3:def 5;
A11: dom b1 = I by PARTFUN1:def 2;
then reconsider bb = bb as ManySortedSet of I by A10, PARTFUN1:def 2, RELAT_1:def 18;
set bbx = bb +* ((indx b1),x);
A12: dom (Carrier A) = I by PARTFUN1:def 2;
A13: {(bb +* ((indx b1),x))} = product (b1 +* ((indx b1),{x}))
proof
thus {(bb +* ((indx b1),x))} c= product (b1 +* ((indx b1),{x})) :: according to XBOOLE_0:def 10 :: thesis: product (b1 +* ((indx b1),{x})) c= {(bb +* ((indx b1),x))}
proof
A14: now
let z be set ; :: thesis: ( z in dom (b1 +* ((indx b1),{x})) implies (bb +* ((indx b1),x)) . b1 in (b1 +* ((indx b1),{x})) . b1 )
assume z in dom (b1 +* ((indx b1),{x})) ; :: thesis: (bb +* ((indx b1),x)) . b1 in (b1 +* ((indx b1),{x})) . b1
then A15: z in I by PARTFUN1:def 2;
then A16: z in dom bb by PARTFUN1:def 2;
per cases ( z = indx b1 or z <> indx b1 ) ;
suppose A17: z = indx b1 ; :: thesis: (bb +* ((indx b1),x)) . b1 in (b1 +* ((indx b1),{x})) . b1
then (bb +* ((indx b1),x)) . z = x by A16, FUNCT_7:31;
then (bb +* ((indx b1),x)) . z in {x} by TARSKI:def 1;
hence (bb +* ((indx b1),x)) . z in (b1 +* ((indx b1),{x})) . z by A11, A17, FUNCT_7:31; :: thesis: verum
end;
suppose A18: z <> indx b1 ; :: thesis: (bb +* ((indx b1),x)) . b1 in (b1 +* ((indx b1),{x})) . b1
then (bb +* ((indx b1),x)) . z = bb . z by FUNCT_7:32;
then (bb +* ((indx b1),x)) . z in b1 . z by A9, A11, A15, CARD_3:9;
hence (bb +* ((indx b1),x)) . z in (b1 +* ((indx b1),{x})) . z by A18, FUNCT_7:32; :: thesis: verum
end;
end;
end;
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in {(bb +* ((indx b1),x))} or o in product (b1 +* ((indx b1),{x})) )
assume o in {(bb +* ((indx b1),x))} ; :: thesis: o in product (b1 +* ((indx b1),{x}))
then A19: o = bb +* ((indx b1),x) by TARSKI:def 1;
dom (bb +* ((indx b1),x)) = I by PARTFUN1:def 2
.= dom (b1 +* ((indx b1),{x})) by PARTFUN1:def 2 ;
hence o in product (b1 +* ((indx b1),{x})) by A19, A14, CARD_3:9; :: thesis: verum
end;
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in product (b1 +* ((indx b1),{x})) or o in {(bb +* ((indx b1),x))} )
assume o in product (b1 +* ((indx b1),{x})) ; :: thesis: o in {(bb +* ((indx b1),x))}
then consider u being Function such that
A20: u = o and
A21: dom u = dom (b1 +* ((indx b1),{x})) and
A22: for z being set st z in dom (b1 +* ((indx b1),{x})) holds
u . z in (b1 +* ((indx b1),{x})) . z by CARD_3:def 5;
A23: now
let z be set ; :: thesis: ( z in dom u implies u . b1 = (bb +* ((indx b1),x)) . b1 )
assume A24: z in dom u ; :: thesis: u . b1 = (bb +* ((indx b1),x)) . b1
then A25: z in I by A21, PARTFUN1:def 2;
reconsider zz = z as Element of I by A21, A24, PARTFUN1:def 2;
A26: u . z in (b1 +* ((indx b1),{x})) . z by A21, A22, A24;
per cases ( zz = indx b1 or zz <> indx b1 ) ;
suppose A27: zz = indx b1 ; :: thesis: u . b1 = (bb +* ((indx b1),x)) . b1
then u . z in {x} by A11, A26, FUNCT_7:31;
then u . z = x by TARSKI:def 1;
hence u . z = (bb +* ((indx b1),x)) . z by A10, A11, A27, FUNCT_7:31; :: thesis: verum
end;
suppose A28: zz <> indx b1 ; :: thesis: u . b1 = (bb +* ((indx b1),x)) . b1
then ( not b1 . zz is empty & b1 . zz is trivial ) by PENCIL_1:def 21;
then b1 . zz is 1 -element ;
then consider o being set such that
A29: b1 . z = {o} by ZFMISC_1:131;
u . z in b1 . z by A26, A28, FUNCT_7:32;
then A30: u . z = o by A29, TARSKI:def 1;
(bb +* ((indx b1),x)) . z = bb . z by A28, FUNCT_7:32;
then (bb +* ((indx b1),x)) . z in {o} by A10, A11, A25, A29;
hence u . z = (bb +* ((indx b1),x)) . z by A30, TARSKI:def 1; :: thesis: verum
end;
end;
end;
dom u = I by A21, PARTFUN1:def 2
.= dom (bb +* ((indx b1),x)) by PARTFUN1:def 2 ;
then u = bb +* ((indx b1),x) by A23, FUNCT_1:2;
hence o in {(bb +* ((indx b1),x))} by A20, TARSKI:def 1; :: thesis: verum
end;
assume A31: x in the carrier of (A . (indx b1)) ; :: thesis: ex y being set st S1[x,y]
A32: now
let o be set ; :: thesis: ( o in dom (Carrier A) implies (bb +* ((indx b1),x)) . b1 in (Carrier A) . b1 )
assume A33: o in dom (Carrier A) ; :: thesis: (bb +* ((indx b1),x)) . b1 in (Carrier A) . b1
then reconsider u = o as Element of I by PARTFUN1:def 2;
per cases ( u = indx b1 or u <> indx b1 ) ;
suppose A34: u = indx b1 ; :: thesis: (bb +* ((indx b1),x)) . b1 in (Carrier A) . b1
then (bb +* ((indx b1),x)) . u in [#] (A . (indx b1)) by A31, A10, A11, FUNCT_7:31;
hence (bb +* ((indx b1),x)) . o in (Carrier A) . o by A34, Th7; :: thesis: verum
end;
suppose A35: u <> indx b1 ; :: thesis: (bb +* ((indx b1),x)) . b1 in (Carrier A) . b1
b1 c= Carrier A by PBOOLE:def 18;
then A36: b1 . o c= (Carrier A) . o by A12, A33, PBOOLE:def 2;
(bb +* ((indx b1),x)) . u = bb . u by A35, FUNCT_7:32;
then (bb +* ((indx b1),x)) . u in b1 . u by A9, A11, CARD_3:9;
hence (bb +* ((indx b1),x)) . o in (Carrier A) . o by A36; :: thesis: verum
end;
end;
end;
dom (bb +* ((indx b1),x)) = I by PARTFUN1:def 2
.= dom (Carrier A) by PARTFUN1:def 2 ;
then reconsider bbx1 = bb +* ((indx b1),x) as Point of (Segre_Product A) by A7, A32, CARD_3:9;
reconsider fbbx = f . bbx1 as ManySortedSet of I by PENCIL_1:14;
take fbbx . ((permutation_of_indices f) . (indx b1)) ; :: thesis: S1[x,fbbx . ((permutation_of_indices f) . (indx b1))]
dom f = the carrier of (Segre_Product A) by FUNCT_2:def 1;
then bbx1 in dom f ;
then A37: Im (f,(bb +* ((indx b1),x))) = {(f . (bb +* ((indx b1),x)))} by FUNCT_1:59;
let J be ManySortedSet of I; :: thesis: ( J in f .: (product (b1 +* ((indx b1),{x}))) implies fbbx . ((permutation_of_indices f) . (indx b1)) = J . ((permutation_of_indices f) . (indx b1)) )
assume J in f .: (product (b1 +* ((indx b1),{x}))) ; :: thesis: fbbx . ((permutation_of_indices f) . (indx b1)) = J . ((permutation_of_indices f) . (indx b1))
hence fbbx . ((permutation_of_indices f) . (indx b1)) = J . ((permutation_of_indices f) . (indx b1)) by A13, A37, TARSKI:def 1; :: thesis: verum
end;
consider M being Function such that
A38: ( dom M = the carrier of (A . (indx b1)) & ( for x being set st x in the carrier of (A . (indx b1)) holds
S1[x,M . x] ) ) from CLASSES1:sch 1(A8);
A39: dom f = the carrier of (Segre_Product A) by FUNCT_2:def 1;
then B1 c= f " B2 by FUNCT_1:76;
then A40: f " B2 = B1 by A6, XBOOLE_0:def 10;
rng M c= the carrier of (A . ((permutation_of_indices f) . (indx b1)))
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in rng M or x in the carrier of (A . ((permutation_of_indices f) . (indx b1))) )
assume x in rng M ; :: thesis: x in the carrier of (A . ((permutation_of_indices f) . (indx b1)))
then consider o being set such that
A41: o in dom M and
A42: x = M . o by FUNCT_1:def 3;
reconsider o = o as Point of (A . (indx b1)) by A38, A41;
consider p being ManySortedSet of I such that
A43: p in product b1 and
A44: {(p +* ((indx b1),o))} = product (b1 +* ((indx b1),{o})) by Th18;
reconsider pio = p +* ((indx b1),o) as Point of (Segre_Product A) by A2, A43, PENCIL_1:25;
reconsider J = f . pio as ManySortedSet of I by PENCIL_1:14;
Im (f,(p +* ((indx b1),o))) = {(f . pio)} by A39, FUNCT_1:59;
then A45: J in f .: (product (b1 +* ((indx b1),{o}))) by A44, TARSKI:def 1;
(permutation_of_indices f) . (indx b1) in I ;
then (permutation_of_indices f) . (indx b1) in dom (Carrier A) by PARTFUN1:def 2;
then J . ((permutation_of_indices f) . (indx b1)) in (Carrier A) . ((permutation_of_indices f) . (indx b1)) by A7, CARD_3:9;
then J . ((permutation_of_indices f) . (indx b1)) in [#] (A . ((permutation_of_indices f) . (indx b1))) by Th7;
hence x in the carrier of (A . ((permutation_of_indices f) . (indx b1))) by A38, A42, A45; :: thesis: verum
end;
then reconsider M = M as Function of (A . (indx b1)),(A . ((permutation_of_indices f) . (indx b1))) by A38, FUNCT_2:def 1, RELSET_1:4;
set m = M;
A46: indx b2 = (permutation_of_indices f) . (indx b1) by A1, A3, Def3;
A47: M is one-to-one
proof
let x1, x2 be set ; :: according to FUNCT_1:def 4 :: thesis: ( not x1 in proj1 M or not x2 in proj1 M or not M . x1 = M . x2 or x1 = x2 )
assume that
A48: ( x1 in dom M & x2 in dom M ) and
A49: M . x1 = M . x2 ; :: thesis: x1 = x2
reconsider o1 = x1, o2 = x2 as Point of (A . (indx b1)) by A48;
consider p1 being ManySortedSet of I such that
A50: p1 in product b1 and
A51: {(p1 +* ((indx b1),o1))} = product (b1 +* ((indx b1),{o1})) by Th18;
reconsider p1io = p1 +* ((indx b1),o1) as Point of (Segre_Product A) by A2, A50, PENCIL_1:25;
reconsider J1 = f . p1io as ManySortedSet of I by PENCIL_1:14;
consider p2 being ManySortedSet of I such that
A52: p2 in product b1 and
A53: {(p2 +* ((indx b1),o2))} = product (b1 +* ((indx b1),{o2})) by Th18;
A54: dom b1 = I by PARTFUN1:def 2;
A55: dom p1 = I by PARTFUN1:def 2;
A56: now
let o be set ; :: thesis: ( o in I implies (p1 +* ((indx b1),o1)) . b1 in b1 . b1 )
assume A57: o in I ; :: thesis: (p1 +* ((indx b1),o1)) . b1 in b1 . b1
per cases ( o = indx b1 or o <> indx b1 ) ;
suppose A58: o = indx b1 ; :: thesis: (p1 +* ((indx b1),o1)) . b1 in b1 . b1
then (p1 +* ((indx b1),o1)) . o = o1 by A55, FUNCT_7:31;
then (p1 +* ((indx b1),o1)) . o in [#] (A . (indx b1)) ;
hence (p1 +* ((indx b1),o1)) . o in b1 . o by A2, A58, Th10; :: thesis: verum
end;
suppose o <> indx b1 ; :: thesis: (p1 +* ((indx b1),o1)) . b1 in b1 . b1
then (p1 +* ((indx b1),o1)) . o = p1 . o by FUNCT_7:32;
hence (p1 +* ((indx b1),o1)) . o in b1 . o by A50, A54, A57, CARD_3:9; :: thesis: verum
end;
end;
end;
dom (p1 +* ((indx b1),o1)) = I by PARTFUN1:def 2;
then p1io in product b1 by A54, A56, CARD_3:9;
then A59: J1 in B2 by A39, FUNCT_1:def 6;
reconsider p2io = p2 +* ((indx b1),o2) as Point of (Segre_Product A) by A2, A52, PENCIL_1:25;
reconsider J2 = f . p2io as ManySortedSet of I by PENCIL_1:14;
Im (f,(p2 +* ((indx b1),o2))) = {(f . p2io)} by A39, FUNCT_1:59;
then J2 in f .: (product (b1 +* ((indx b1),{o2}))) by A53, TARSKI:def 1;
then A60: M . o2 = J2 . ((permutation_of_indices f) . (indx b1)) by A38;
dom p1 = I by PARTFUN1:def 2;
then A61: (p1 +* ((indx b1),o1)) . (indx b1) = o1 by FUNCT_7:31;
A62: dom b1 = I by PARTFUN1:def 2;
A63: dom p2 = I by PARTFUN1:def 2;
A64: now
let o be set ; :: thesis: ( o in I implies (p2 +* ((indx b1),o2)) . b1 in b1 . b1 )
assume A65: o in I ; :: thesis: (p2 +* ((indx b1),o2)) . b1 in b1 . b1
per cases ( o = indx b1 or o <> indx b1 ) ;
suppose A66: o = indx b1 ; :: thesis: (p2 +* ((indx b1),o2)) . b1 in b1 . b1
then (p2 +* ((indx b1),o2)) . o = o2 by A63, FUNCT_7:31;
then (p2 +* ((indx b1),o2)) . o in [#] (A . (indx b1)) ;
hence (p2 +* ((indx b1),o2)) . o in b1 . o by A2, A66, Th10; :: thesis: verum
end;
suppose o <> indx b1 ; :: thesis: (p2 +* ((indx b1),o2)) . b1 in b1 . b1
then (p2 +* ((indx b1),o2)) . o = p2 . o by FUNCT_7:32;
hence (p2 +* ((indx b1),o2)) . o in b1 . o by A52, A62, A65, CARD_3:9; :: thesis: verum
end;
end;
end;
dom (p2 +* ((indx b1),o2)) = I by PARTFUN1:def 2;
then p2io in product b1 by A62, A64, CARD_3:9;
then A67: J2 in B2 by A39, FUNCT_1:def 6;
Im (f,(p1 +* ((indx b1),o1))) = {(f . p1io)} by A39, FUNCT_1:59;
then A68: J1 in f .: (product (b1 +* ((indx b1),{o1}))) by A51, TARSKI:def 1;
A69: now
let o be set ; :: thesis: ( o in I implies J1 . b1 = J2 . b1 )
assume o in I ; :: thesis: J1 . b1 = J2 . b1
then reconsider l = o as Element of I ;
per cases ( l = indx b2 or l <> indx b2 ) ;
suppose l = indx b2 ; :: thesis: J1 . b1 = J2 . b1
hence J1 . o = J2 . o by A46, A38, A49, A68, A60; :: thesis: verum
end;
suppose l <> indx b2 ; :: thesis: J1 . b1 = J2 . b1
hence J1 . o = J2 . o by A3, A59, A67, PENCIL_1:23; :: thesis: verum
end;
end;
end;
dom p2 = I by PARTFUN1:def 2;
then A70: (p2 +* ((indx b1),o2)) . (indx b1) = o2 by FUNCT_7:31;
( dom J1 = I & dom J2 = I ) by PARTFUN1:def 2;
then J1 = J2 by A69, FUNCT_1:2;
hence x1 = x2 by A39, A5, A61, A70, FUNCT_1:def 4; :: thesis: verum
end;
f is bijective by PENCIL_2:def 4;
then A71: rng f = the carrier of (Segre_Product A) by FUNCT_2:def 3;
A72: f " = f " by A5, TOPS_2:def 4;
the carrier of (A . ((permutation_of_indices f) . (indx b1))) c= rng M
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in the carrier of (A . ((permutation_of_indices f) . (indx b1))) or x in rng M )
assume x in the carrier of (A . ((permutation_of_indices f) . (indx b1))) ; :: thesis: x in rng M
then reconsider x1 = x as Point of (A . ((permutation_of_indices f) . (indx b1))) ;
consider p0 being ManySortedSet of I such that
A73: p0 in product b2 and
{(p0 +* ((indx b2),x1))} = product (b2 +* ((indx b2),{x1})) by A46, Th18;
reconsider p = p0 +* ((indx b2),x1) as Point of (Segre_Product A) by A3, A46, A73, PENCIL_1:25;
reconsider p1 = p as ManySortedSet of I ;
reconsider q = (f ") . p as ManySortedSet of I by PENCIL_1:14;
A74: p = f . ((f ") . p) by A71, A5, A72, FUNCT_1:35;
A75: dom b1 = I by PARTFUN1:def 2;
A76: now
let o be set ; :: thesis: ( o in I implies q . b1 in (b1 +* ((indx b1),{(q . (indx b1))})) . b1 )
assume o in I ; :: thesis: q . b1 in (b1 +* ((indx b1),{(q . (indx b1))})) . b1
then reconsider l = o as Element of I ;
per cases ( l = indx b1 or l <> indx b1 ) ;
suppose l = indx b1 ; :: thesis: q . b1 in (b1 +* ((indx b1),{(q . (indx b1))})) . b1
then (b1 +* ((indx b1),{(q . (indx b1))})) . l = {(q . o)} by A75, FUNCT_7:31;
hence q . o in (b1 +* ((indx b1),{(q . (indx b1))})) . o by TARSKI:def 1; :: thesis: verum
end;
suppose l <> indx b1 ; :: thesis: q . b1 in (b1 +* ((indx b1),{(q . (indx b1))})) . b1
then A77: (b1 +* ((indx b1),{(q . (indx b1))})) . l = b1 . l by FUNCT_7:32;
A78: dom b2 = I by PARTFUN1:def 2;
A79: dom p0 = I by PARTFUN1:def 2;
A80: now
let o be set ; :: thesis: ( o in I implies p1 . b1 in b2 . b1 )
assume A81: o in I ; :: thesis: p1 . b1 in b2 . b1
per cases ( o = indx b2 or o <> indx b2 ) ;
suppose A82: o = indx b2 ; :: thesis: p1 . b1 in b2 . b1
then p1 . o = x1 by A79, FUNCT_7:31;
then p1 . o in the carrier of (A . ((permutation_of_indices f) . (indx b1))) ;
hence p1 . o in b2 . o by A1, A3, A4, A82, Def3; :: thesis: verum
end;
suppose o <> indx b2 ; :: thesis: p1 . b1 in b2 . b1
then p1 . o = p0 . o by FUNCT_7:32;
hence p1 . o in b2 . o by A73, A78, A81, CARD_3:9; :: thesis: verum
end;
end;
end;
dom p1 = I by PARTFUN1:def 2;
then p in product b2 by A78, A80, CARD_3:9;
then consider q0 being set such that
A83: q0 in dom f and
A84: q0 in B1 and
A85: p = f . q0 by A3, FUNCT_1:def 6;
q = q0 by A39, A5, A74, A83, A85, FUNCT_1:def 4;
hence q . o in (b1 +* ((indx b1),{(q . (indx b1))})) . o by A75, A77, A84, CARD_3:9; :: thesis: verum
end;
end;
end;
I = dom (Carrier A) by PARTFUN1:def 2;
then q . (indx b1) in (Carrier A) . (indx b1) by A7, CARD_3:9;
then A86: q . (indx b1) in [#] (A . (indx b1)) by Th7;
( dom q = I & dom (b1 +* ((indx b1),{(q . (indx b1))})) = I ) by PARTFUN1:def 2;
then q in product (b1 +* ((indx b1),{(q . (indx b1))})) by A76, CARD_3:9;
then p0 +* ((indx b2),x1) in f .: (product (b1 +* ((indx b1),{(q . (indx b1))}))) by A39, A74, FUNCT_1:def 6;
then ( dom p0 = I & M . (q . (indx b1)) = (p0 +* ((indx b2),x1)) . ((permutation_of_indices f) . (indx b1)) ) by A38, A86, PARTFUN1:def 2;
then ( dom M = the carrier of (A . (indx b1)) & M . (q . (indx b1)) = x ) by A46, FUNCT_2:def 1, FUNCT_7:31;
hence x in rng M by A86, FUNCT_1:3; :: thesis: verum
end;
then A87: rng M = the carrier of (A . ((permutation_of_indices f) . (indx b1))) by XBOOLE_0:def 10;
then M is onto by FUNCT_2:def 3;
then A88: M " = M " by A47, TOPS_2:def 4;
A89: M " is open
proof
let S0 be Subset of (A . ((permutation_of_indices f) . (indx b1))); :: according to T_0TOPSP:def 2 :: thesis: ( not S0 is open or (M ") .: S0 is open )
assume S0 is open ; :: thesis: (M ") .: S0 is open
then reconsider S = S0 as Block of (A . ((permutation_of_indices f) . (indx b1))) by PRE_TOPC:def 2;
reconsider L = product (b2 +* ((indx b2),S)) as Block of (Segre_Product A) by A46, Th12;
reconsider K = f " L as Block of (Segre_Product A) ;
consider k being non trivial-yielding Segre-like ManySortedSubset of Carrier A such that
A90: K = product k and
A91: k . (indx k) is Block of (A . (indx k)) by PENCIL_1:24;
A92: dom b2 = I by PARTFUN1:def 2;
A93: now
let x be set ; :: thesis: ( x in I implies (b2 +* ((indx b2),S)) . b1 c= b2 . b1 )
assume x in I ; :: thesis: (b2 +* ((indx b2),S)) . b1 c= b2 . b1
per cases ( x = indx b2 or x <> indx b2 ) ;
suppose A94: x = indx b2 ; :: thesis: (b2 +* ((indx b2),S)) . b1 c= b2 . b1
then (b2 +* ((indx b2),S)) . x = S by A92, FUNCT_7:31;
then (b2 +* ((indx b2),S)) . x c= the carrier of (A . ((permutation_of_indices f) . (indx b1))) ;
hence (b2 +* ((indx b2),S)) . x c= b2 . x by A1, A3, A4, A94, Def3; :: thesis: verum
end;
suppose x <> indx b2 ; :: thesis: (b2 +* ((indx b2),S)) . b1 c= b2 . b1
hence (b2 +* ((indx b2),S)) . x c= b2 . x by FUNCT_7:32; :: thesis: verum
end;
end;
end;
dom (b2 +* ((indx b2),S)) = I by PARTFUN1:def 2;
then L c= product b2 by A92, A93, CARD_3:27;
then (product b1) /\ (product k) = K by A3, A40, A90, RELAT_1:143, XBOOLE_1:28;
then A95: 2 c= card ((product b1) /\ (product k)) by PENCIL_1:def 6;
then A96: indx k = indx b1 by PENCIL_1:26;
M " S = k . (indx k)
proof
thus M " S c= k . (indx k) :: according to XBOOLE_0:def 10 :: thesis: k . (indx k) c= M " S
proof
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in M " S or o in k . (indx k) )
A97: dom b2 = I by PARTFUN1:def 2;
assume A98: o in M " S ; :: thesis: o in k . (indx k)
then reconsider u = o as Point of (A . (indx b1)) ;
consider p being ManySortedSet of I such that
A99: p in product b1 and
A100: {(p +* ((indx b1),u))} = product (b1 +* ((indx b1),{u})) by Th18;
reconsider q = p +* ((indx b1),u) as Point of (Segre_Product A) by A2, A99, PENCIL_1:25;
reconsider fq = f . q as ManySortedSet of I by PENCIL_1:14;
Im (f,(p +* ((indx b1),u))) = {(f . q)} by A39, FUNCT_1:59;
then A101: fq in f .: (product (b1 +* ((indx b1),{u}))) by A100, TARSKI:def 1;
product (b1 +* ((indx b1),{u})) c= product b1
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in product (b1 +* ((indx b1),{u})) or a in product b1 )
A102: dom b1 = I by PARTFUN1:def 2;
assume a in product (b1 +* ((indx b1),{u})) ; :: thesis: a in product b1
then consider g being Function such that
A103: a = g and
A104: dom g = dom (b1 +* ((indx b1),{u})) and
A105: for o being set st o in dom (b1 +* ((indx b1),{u})) holds
g . o in (b1 +* ((indx b1),{u})) . o by CARD_3:def 5;
A106: dom g = I by A104, PARTFUN1:def 2;
now
let o be set ; :: thesis: ( o in I implies g . b1 in b1 . b1 )
assume o in I ; :: thesis: g . b1 in b1 . b1
then A107: g . o in (b1 +* ((indx b1),{u})) . o by A104, A105, A106;
per cases ( o = indx b1 or o <> indx b1 ) ;
suppose A108: o = indx b1 ; :: thesis: g . b1 in b1 . b1
then g . o in {u} by A102, A107, FUNCT_7:31;
then g . o in [#] (A . (indx b1)) ;
hence g . o in b1 . o by A2, A108, Th10; :: thesis: verum
end;
suppose o <> indx b1 ; :: thesis: g . b1 in b1 . b1
hence g . o in b1 . o by A107, FUNCT_7:32; :: thesis: verum
end;
end;
end;
hence a in product b1 by A103, A106, A102, CARD_3:9; :: thesis: verum
end;
then A109: f .: (product (b1 +* ((indx b1),{u}))) c= product b2 by A3, RELAT_1:123;
M . o in S by A98, FUNCT_1:def 7;
then A110: fq . ((permutation_of_indices f) . (indx b1)) in S by A38, A101;
A111: now
let o be set ; :: thesis: ( o in I implies fq . b1 in (b2 +* ((indx b2),S)) . b1 )
assume A112: o in I ; :: thesis: fq . b1 in (b2 +* ((indx b2),S)) . b1
per cases ( o = indx b2 or o <> indx b2 ) ;
suppose o = indx b2 ; :: thesis: fq . b1 in (b2 +* ((indx b2),S)) . b1
hence fq . o in (b2 +* ((indx b2),S)) . o by A46, A110, A97, FUNCT_7:31; :: thesis: verum
end;
suppose o <> indx b2 ; :: thesis: fq . b1 in (b2 +* ((indx b2),S)) . b1
then (b2 +* ((indx b2),S)) . o = b2 . o by FUNCT_7:32;
hence fq . o in (b2 +* ((indx b2),S)) . o by A101, A109, A97, A112, CARD_3:9; :: thesis: verum
end;
end;
end;
( dom fq = I & dom (b2 +* ((indx b2),S)) = I ) by PARTFUN1:def 2;
then fq in L by A111, CARD_3:9;
then ( dom k = I & q in K ) by A39, FUNCT_1:def 7, PARTFUN1:def 2;
then ( dom p = I & (p +* ((indx b1),u)) . (indx b1) in k . (indx b1) ) by A90, CARD_3:9, PARTFUN1:def 2;
hence o in k . (indx k) by A96, FUNCT_7:31; :: thesis: verum
end;
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in k . (indx k) or o in M " S )
assume A113: o in k . (indx k) ; :: thesis: o in M " S
k . (indx k) in the topology of (A . (indx b1)) by A91, A96;
then reconsider u = o as Point of (A . (indx b1)) by A113;
consider p0 being ManySortedSet of I such that
A114: p0 in product b1 and
A115: {(p0 +* ((indx b1),u))} = product (b1 +* ((indx b1),{u})) by Th18;
reconsider p = p0 +* ((indx b1),u) as Point of (Segre_Product A) by A2, A114, PENCIL_1:25;
reconsider fp = f . p as ManySortedSet of I by PENCIL_1:14;
A116: dom b1 = I by PARTFUN1:def 2;
A117: dom p0 = I by PARTFUN1:def 2;
A118: now
let a be set ; :: thesis: ( a in I implies (p0 +* ((indx b1),u)) . b1 in k . b1 )
assume A119: a in I ; :: thesis: (p0 +* ((indx b1),u)) . b1 in k . b1
per cases ( a = indx b1 or a <> indx b1 ) ;
suppose a = indx b1 ; :: thesis: (p0 +* ((indx b1),u)) . b1 in k . b1
hence (p0 +* ((indx b1),u)) . a in k . a by A96, A113, A117, FUNCT_7:31; :: thesis: verum
end;
suppose A120: a <> indx b1 ; :: thesis: (p0 +* ((indx b1),u)) . b1 in k . b1
then (p0 +* ((indx b1),u)) . a = p0 . a by FUNCT_7:32;
then (p0 +* ((indx b1),u)) . a in b1 . a by A114, A116, A119, CARD_3:9;
hence (p0 +* ((indx b1),u)) . a in k . a by A95, A120, PENCIL_1:26; :: thesis: verum
end;
end;
end;
( dom (p0 +* ((indx b1),u)) = I & dom k = I ) by PARTFUN1:def 2;
then p in K by A90, A118, CARD_3:9;
then ( dom (b2 +* ((indx b2),S)) = I & fp in L ) by FUNCT_1:def 7, PARTFUN1:def 2;
then ( dom b2 = I & fp . (indx b2) in (b2 +* ((indx b2),S)) . (indx b2) ) by CARD_3:9, PARTFUN1:def 2;
then A121: fp . ((permutation_of_indices f) . (indx b1)) in S by A46, FUNCT_7:31;
Im (f,(p0 +* ((indx b1),u))) = {(f . p)} by A39, FUNCT_1:59;
then fp in f .: (product (b1 +* ((indx b1),{u}))) by A115, TARSKI:def 1;
then M . u = fp . ((permutation_of_indices f) . (indx b1)) by A38;
hence o in M " S by A38, A121, FUNCT_1:def 7; :: thesis: verum
end;
then (M ") .: S is Block of (A . (indx b1)) by A47, A88, A91, A96, FUNCT_1:85;
hence (M ") .: S0 is open by PRE_TOPC:def 2; :: thesis: verum
end;
A122: M is open
proof
let S0 be Subset of (A . (indx b1)); :: according to T_0TOPSP:def 2 :: thesis: ( not S0 is open or M .: S0 is open )
assume S0 is open ; :: thesis: M .: S0 is open
then reconsider S = S0 as Block of (A . (indx b1)) by PRE_TOPC:def 2;
reconsider L = product (b1 +* ((indx b1),S)) as Block of (Segre_Product A) by Th12;
reconsider K = f .: L as Block of (Segre_Product A) ;
consider k being non trivial-yielding Segre-like ManySortedSubset of Carrier A such that
A123: K = product k and
A124: k . (indx k) is Block of (A . (indx k)) by PENCIL_1:24;
A125: dom b1 = I by PARTFUN1:def 2;
A126: now
let x be set ; :: thesis: ( x in I implies (b1 +* ((indx b1),S)) . b1 c= b1 . b1 )
assume x in I ; :: thesis: (b1 +* ((indx b1),S)) . b1 c= b1 . b1
per cases ( x = indx b1 or x <> indx b1 ) ;
suppose A127: x = indx b1 ; :: thesis: (b1 +* ((indx b1),S)) . b1 c= b1 . b1
then (b1 +* ((indx b1),S)) . x = S by A125, FUNCT_7:31;
then (b1 +* ((indx b1),S)) . x c= [#] (A . (indx b1)) ;
hence (b1 +* ((indx b1),S)) . x c= b1 . x by A2, A127, Th10; :: thesis: verum
end;
suppose x <> indx b1 ; :: thesis: (b1 +* ((indx b1),S)) . b1 c= b1 . b1
hence (b1 +* ((indx b1),S)) . x c= b1 . x by FUNCT_7:32; :: thesis: verum
end;
end;
end;
dom (b1 +* ((indx b1),S)) = I by PARTFUN1:def 2;
then A128: L c= product b1 by A125, A126, CARD_3:27;
then (product b2) /\ (product k) = K by A3, A123, RELAT_1:123, XBOOLE_1:28;
then 2 c= card ((product b2) /\ (product k)) by PENCIL_1:def 6;
then A129: indx k = (permutation_of_indices f) . (indx b1) by A46, PENCIL_1:26;
A130: dom k = I by PARTFUN1:def 2;
M .: S = k . (indx k)
proof
thus M .: S c= k . (indx k) :: according to XBOOLE_0:def 10 :: thesis: k . (indx k) c= M .: S
proof
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in M .: S or o in k . (indx k) )
A131: dom b1 = I by PARTFUN1:def 2;
assume o in M .: S ; :: thesis: o in k . (indx k)
then consider u being set such that
A132: u in dom M and
A133: u in S and
A134: o = M . u by FUNCT_1:def 6;
reconsider u = u as Point of (A . (indx b1)) by A132;
consider p0 being ManySortedSet of I such that
A135: p0 in product b1 and
A136: {(p0 +* ((indx b1),u))} = product (b1 +* ((indx b1),{u})) by Th18;
reconsider p = p0 +* ((indx b1),u) as Point of (Segre_Product A) by A2, A135, PENCIL_1:25;
reconsider q = f . p as ManySortedSet of I by PENCIL_1:14;
Im (f,(p0 +* ((indx b1),u))) = {(f . p)} by A39, FUNCT_1:59;
then q in f .: (product (b1 +* ((indx b1),{u}))) by A136, TARSKI:def 1;
then A137: M . u = q . ((permutation_of_indices f) . (indx b1)) by A38;
A138: dom p0 = I by PARTFUN1:def 2;
A139: now
let a be set ; :: thesis: ( a in I implies (p0 +* ((indx b1),u)) . b1 in (b1 +* ((indx b1),S)) . b1 )
assume A140: a in I ; :: thesis: (p0 +* ((indx b1),u)) . b1 in (b1 +* ((indx b1),S)) . b1
per cases ( a = indx b1 or a <> indx b1 ) ;
suppose A141: a = indx b1 ; :: thesis: (p0 +* ((indx b1),u)) . b1 in (b1 +* ((indx b1),S)) . b1
then (p0 +* ((indx b1),u)) . a = u by A138, FUNCT_7:31;
hence (p0 +* ((indx b1),u)) . a in (b1 +* ((indx b1),S)) . a by A133, A131, A141, FUNCT_7:31; :: thesis: verum
end;
suppose A142: a <> indx b1 ; :: thesis: (p0 +* ((indx b1),u)) . b1 in (b1 +* ((indx b1),S)) . b1
then (p0 +* ((indx b1),u)) . a = p0 . a by FUNCT_7:32;
then (p0 +* ((indx b1),u)) . a in b1 . a by A135, A131, A140, CARD_3:9;
hence (p0 +* ((indx b1),u)) . a in (b1 +* ((indx b1),S)) . a by A142, FUNCT_7:32; :: thesis: verum
end;
end;
end;
( dom (p0 +* ((indx b1),u)) = I & dom (b1 +* ((indx b1),S)) = I ) by PARTFUN1:def 2;
then p in L by A139, CARD_3:9;
then q in product k by A39, A123, FUNCT_1:def 6;
hence o in k . (indx k) by A130, A129, A134, A137, CARD_3:9; :: thesis: verum
end;
let o be set ; :: according to TARSKI:def 3 :: thesis: ( not o in k . (indx k) or o in M .: S )
assume A143: o in k . (indx k) ; :: thesis: o in M .: S
k . (indx k) in the topology of (A . ((permutation_of_indices f) . (indx b1))) by A124, A129;
then reconsider u = o as Point of (A . ((permutation_of_indices f) . (indx b1))) by A143;
consider p0 being ManySortedSet of I such that
A144: p0 in product k and
{(p0 +* (((permutation_of_indices f) . (indx b1)),u))} = product (k +* (((permutation_of_indices f) . (indx b1)),{u})) by A129, Th18;
K in the topology of (Segre_Product A) ;
then reconsider p = p0 +* (((permutation_of_indices f) . (indx b1)),u) as Point of (Segre_Product A) by A123, A144, PENCIL_1:25;
reconsider q = (f ") . p as ManySortedSet of I by PENCIL_1:14;
A145: dom k = I by PARTFUN1:def 2;
A146: dom p0 = I by PARTFUN1:def 2;
A147: now
let z be set ; :: thesis: ( z in I implies (p0 +* (((permutation_of_indices f) . (indx b1)),u)) . b1 in k . b1 )
assume A148: z in I ; :: thesis: (p0 +* (((permutation_of_indices f) . (indx b1)),u)) . b1 in k . b1
end;
A149: p = f . q by A71, A5, A72, FUNCT_1:35;
dom (p0 +* (((permutation_of_indices f) . (indx b1)),u)) = I by PARTFUN1:def 2;
then p in f .: L by A123, A145, A147, CARD_3:9;
then ex qq being set st
( qq in dom f & qq in L & p = f . qq ) by FUNCT_1:def 6;
then A150: q in L by A39, A5, A149, FUNCT_1:def 4;
dom (b1 +* ((indx b1),S)) = I by PARTFUN1:def 2;
then q . (indx b1) in (b1 +* ((indx b1),S)) . (indx b1) by A150, CARD_3:9;
then A151: q . (indx b1) in S by A125, FUNCT_7:31;
then reconsider qi = q . (indx b1) as Point of (A . (indx b1)) ;
consider q0 being ManySortedSet of I such that
A152: q0 in product b1 and
A153: {(q0 +* ((indx b1),qi))} = product (b1 +* ((indx b1),{qi})) by Th18;
A154: dom q0 = I by PARTFUN1:def 2;
A155: now
let a be set ; :: thesis: ( a in I implies (q0 +* ((indx b1),qi)) . b1 = q . b1 )
assume a in I ; :: thesis: (q0 +* ((indx b1),qi)) . b1 = q . b1
per cases ( a = indx b1 or a <> indx b1 ) ;
suppose a = indx b1 ; :: thesis: (q0 +* ((indx b1),qi)) . b1 = q . b1
hence (q0 +* ((indx b1),qi)) . a = q . a by A154, FUNCT_7:31; :: thesis: verum
end;
suppose A156: a <> indx b1 ; :: thesis: (q0 +* ((indx b1),qi)) . b1 = q . b1
then (q0 +* ((indx b1),qi)) . a = q0 . a by FUNCT_7:32;
hence (q0 +* ((indx b1),qi)) . a = q . a by A128, A150, A152, A156, PENCIL_1:23; :: thesis: verum
end;
end;
end;
( dom q = I & dom (q0 +* ((indx b1),qi)) = I ) by PARTFUN1:def 2;
then q0 +* ((indx b1),qi) = q by A155, FUNCT_1:2;
then Im (f,(q0 +* ((indx b1),qi))) = {(f . q)} by A39, FUNCT_1:59;
then p in f .: (product (b1 +* ((indx b1),{qi}))) by A149, A153, TARSKI:def 1;
then M . (q . (indx b1)) = (p0 +* (((permutation_of_indices f) . (indx b1)),u)) . ((permutation_of_indices f) . (indx b1)) by A38;
then M . (q . (indx b1)) = o by A146, FUNCT_7:31;
hence o in M .: S by A38, A151, FUNCT_1:def 6; :: thesis: verum
end;
hence M .: S0 is open by A124, A129, PRE_TOPC:def 2; :: thesis: verum
end;
take M ; :: thesis: ( M is isomorphic & ( for a being ManySortedSet of I st a is Point of (Segre_Product A) & a in product b1 holds
for b being ManySortedSet of I st b = f . a holds
b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1)) ) )

A157: M is onto by A87, FUNCT_2:def 3;
then M " is bijective by A47, PENCIL_2:12;
hence M is isomorphic by A47, A157, A122, A89, PENCIL_2:def 4; :: thesis: for a being ManySortedSet of I st a is Point of (Segre_Product A) & a in product b1 holds
for b being ManySortedSet of I st b = f . a holds
b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1))

let a be ManySortedSet of I; :: thesis: ( a is Point of (Segre_Product A) & a in product b1 implies for b being ManySortedSet of I st b = f . a holds
b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1)) )

assume that
A158: a is Point of (Segre_Product A) and
A159: a in product b1 ; :: thesis: for b being ManySortedSet of I st b = f . a holds
b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1))

dom (Carrier A) = I by PARTFUN1:def 2;
then a . (indx b1) in (Carrier A) . (indx b1) by A7, A158, CARD_3:9;
then a . (indx b1) in [#] (A . (indx b1)) by Th7;
then reconsider ai = a . (indx b1) as Point of (A . (indx b1)) ;
A160: dom b1 = I by PARTFUN1:def 2;
A161: now
let o be set ; :: thesis: ( o in I implies a . b1 in (b1 +* ((indx b1),{ai})) . b1 )
assume A162: o in I ; :: thesis: a . b1 in (b1 +* ((indx b1),{ai})) . b1
per cases ( o = indx b1 or o <> indx b1 ) ;
suppose A163: o = indx b1 ; :: thesis: a . b1 in (b1 +* ((indx b1),{ai})) . b1
then (b1 +* ((indx b1),{ai})) . o = {ai} by A160, FUNCT_7:31;
hence a . o in (b1 +* ((indx b1),{ai})) . o by A163, TARSKI:def 1; :: thesis: verum
end;
suppose o <> indx b1 ; :: thesis: a . b1 in (b1 +* ((indx b1),{ai})) . b1
then (b1 +* ((indx b1),{ai})) . o = b1 . o by FUNCT_7:32;
hence a . o in (b1 +* ((indx b1),{ai})) . o by A159, A160, A162, CARD_3:9; :: thesis: verum
end;
end;
end;
( dom a = I & dom (b1 +* ((indx b1),{ai})) = I ) by PARTFUN1:def 2;
then A164: a in product (b1 +* ((indx b1),{ai})) by A161, CARD_3:9;
let b be ManySortedSet of I; :: thesis: ( b = f . a implies b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1)) )
assume b = f . a ; :: thesis: b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1))
then b in f .: (product (b1 +* ((indx b1),{ai}))) by A39, A158, A164, FUNCT_1:def 6;
hence b . ((permutation_of_indices f) . (indx b1)) = M . (a . (indx b1)) by A38; :: thesis: verum