let f, g be Function of I[01] ,(TOP-REAL 2); :: thesis: for K0 being Subset of (TOP-REAL 2)
for O, I being Point of I[01] st O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & K0 = { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } & (f . O) `1 = - 1 & (f . I) `1 = 1 & - 1 <= (f . O) `2 & (f . O) `2 <= 1 & - 1 <= (f . I) `2 & (f . I) `2 <= 1 & (g . O) `2 = - 1 & (g . I) `2 = 1 & - 1 <= (g . O) `1 & (g . O) `1 <= 1 & - 1 <= (g . I) `1 & (g . I) `1 <= 1 & rng f misses K0 & rng g misses K0 holds
rng f meets rng g

let K0 be Subset of (TOP-REAL 2); :: thesis: for O, I being Point of I[01] st O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & K0 = { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } & (f . O) `1 = - 1 & (f . I) `1 = 1 & - 1 <= (f . O) `2 & (f . O) `2 <= 1 & - 1 <= (f . I) `2 & (f . I) `2 <= 1 & (g . O) `2 = - 1 & (g . I) `2 = 1 & - 1 <= (g . O) `1 & (g . O) `1 <= 1 & - 1 <= (g . I) `1 & (g . I) `1 <= 1 & rng f misses K0 & rng g misses K0 holds
rng f meets rng g

let O, I be Point of I[01] ; :: thesis: ( O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & K0 = { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } & (f . O) `1 = - 1 & (f . I) `1 = 1 & - 1 <= (f . O) `2 & (f . O) `2 <= 1 & - 1 <= (f . I) `2 & (f . I) `2 <= 1 & (g . O) `2 = - 1 & (g . I) `2 = 1 & - 1 <= (g . O) `1 & (g . O) `1 <= 1 & - 1 <= (g . I) `1 & (g . I) `1 <= 1 & rng f misses K0 & rng g misses K0 implies rng f meets rng g )
assume A1: ( O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & K0 = { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } & (f . O) `1 = - 1 & (f . I) `1 = 1 & - 1 <= (f . O) `2 & (f . O) `2 <= 1 & - 1 <= (f . I) `2 & (f . I) `2 <= 1 & (g . O) `2 = - 1 & (g . I) `2 = 1 & - 1 <= (g . O) `1 & (g . O) `1 <= 1 & - 1 <= (g . I) `1 & (g . I) `1 <= 1 & (rng f) /\ K0 = {} & (rng g) /\ K0 = {} ) ; :: according to XBOOLE_0:def 7 :: thesis: rng f meets rng g
defpred S1[ Point of (TOP-REAL 2)] means ( ( - 1 = $1 `1 & - 1 <= $1 `2 & $1 `2 <= 1 ) or ( $1 `1 = 1 & - 1 <= $1 `2 & $1 `2 <= 1 ) or ( - 1 = $1 `2 & - 1 <= $1 `1 & $1 `1 <= 1 ) or ( 1 = $1 `2 & - 1 <= $1 `1 & $1 `1 <= 1 ) );
reconsider Kb = { q where q is Point of (TOP-REAL 2) : S1[q] } as Subset of (TOP-REAL 2) from JGRAPH_2:sch 1();
reconsider B = {(0. (TOP-REAL 2))} as Subset of (TOP-REAL 2) ;
consider h being Function of ((TOP-REAL 2) | (B ` )),((TOP-REAL 2) | (B ` )) such that
A2: ( h is continuous & h is one-to-one & ( for t being Point of (TOP-REAL 2) st t in K0 & t <> 0. (TOP-REAL 2) holds
not h . t in K0 \/ Kb ) & ( for r being Point of (TOP-REAL 2) st not r in K0 \/ Kb holds
h . r in K0 ) & ( for s being Point of (TOP-REAL 2) st s in Kb holds
h . s = s ) ) by A1, Th51;
A3: dom f = the carrier of I[01] by FUNCT_2:def 1;
A4: dom g = the carrier of I[01] by FUNCT_2:def 1;
A5: B ` <> {} by Th19;
rng f c= B `
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in rng f or x in B ` )
assume A6: x in rng f ; :: thesis: x in B `
now end;
then x in the carrier of (TOP-REAL 2) \ B by A6, XBOOLE_0:def 5;
hence x in B ` by SUBSET_1:def 5; :: thesis: verum
end;
then consider w being Function of I[01] ,(TOP-REAL 2) such that
A8: ( w is continuous & w = h * f ) by A1, A2, A5, Th22;
reconsider d1 = h * f as Function of I[01] ,(TOP-REAL 2) by A8;
A9: the carrier of ((TOP-REAL 2) | (B ` )) = [#] ((TOP-REAL 2) | (B ` ))
.= B ` by PRE_TOPC:def 10 ;
rng f c= the carrier of (TOP-REAL 2) \ B
proof
let e be set ; :: according to TARSKI:def 3 :: thesis: ( not e in rng f or e in the carrier of (TOP-REAL 2) \ B )
assume A10: e in rng f ; :: thesis: e in the carrier of (TOP-REAL 2) \ B
now
assume e in B ; :: thesis: contradiction
then A11: e = 0. (TOP-REAL 2) by TARSKI:def 1;
0. (TOP-REAL 2) in { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } by Th11;
hence contradiction by A1, A10, A11, XBOOLE_0:def 4; :: thesis: verum
end;
hence e in the carrier of (TOP-REAL 2) \ B by A10, XBOOLE_0:def 5; :: thesis: verum
end;
then A12: rng f c= the carrier of ((TOP-REAL 2) | (B ` )) by A9, SUBSET_1:def 5;
A13: d1 is one-to-one by A1, A2, FUNCT_1:46;
rng g c= B `
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in rng g or x in B ` )
assume A14: x in rng g ; :: thesis: x in B `
now end;
then x in the carrier of (TOP-REAL 2) \ B by A14, XBOOLE_0:def 5;
hence x in B ` by SUBSET_1:def 5; :: thesis: verum
end;
then consider w2 being Function of I[01] ,(TOP-REAL 2) such that
A16: ( w2 is continuous & w2 = h * g ) by A1, A2, A5, Th22;
reconsider d2 = h * g as Function of I[01] ,(TOP-REAL 2) by A16;
rng g c= the carrier of (TOP-REAL 2) \ B
proof
let e be set ; :: according to TARSKI:def 3 :: thesis: ( not e in rng g or e in the carrier of (TOP-REAL 2) \ B )
assume A17: e in rng g ; :: thesis: e in the carrier of (TOP-REAL 2) \ B
now
assume e in B ; :: thesis: contradiction
then A18: e = 0. (TOP-REAL 2) by TARSKI:def 1;
0. (TOP-REAL 2) in { p where p is Point of (TOP-REAL 2) : ( - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) } by Th11;
hence contradiction by A1, A17, A18, XBOOLE_0:def 4; :: thesis: verum
end;
hence e in the carrier of (TOP-REAL 2) \ B by A17, XBOOLE_0:def 5; :: thesis: verum
end;
then A19: rng g c= the carrier of ((TOP-REAL 2) | (B ` )) by A9, SUBSET_1:def 5;
A20: d2 is one-to-one by A1, A2, FUNCT_1:46;
f . O in Kb by A1;
then A21: h . (f . O) = f . O by A2;
f . I in Kb by A1;
then A22: h . (f . I) = f . I by A2;
g . O in Kb by A1;
then A23: h . (g . O) = g . O by A2;
g . I in Kb by A1;
then h . (g . I) = g . I by A2;
then A24: ( (d1 . O) `1 = - 1 & (d1 . I) `1 = 1 & (d2 . O) `2 = - 1 & (d2 . I) `2 = 1 ) by A1, A3, A4, A21, A22, A23, FUNCT_1:23;
for r being Point of I[01] holds
( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
proof
let r be Point of I[01] ; :: thesis: ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
f . r in rng f by A3, FUNCT_1:12;
then A25: not f . r in K0 by A1, XBOOLE_0:def 4;
A26: ( not f . r in Kb implies d1 . r in K0 \/ Kb )
proof
assume not f . r in Kb ; :: thesis: d1 . r in K0 \/ Kb
then not f . r in K0 \/ Kb by A25, XBOOLE_0:def 3;
then A27: h . (f . r) in K0 by A2;
d1 . r = h . (f . r) by A3, FUNCT_1:23;
hence d1 . r in K0 \/ Kb by A27, XBOOLE_0:def 3; :: thesis: verum
end;
A28: ( f . r in Kb implies d1 . r in K0 \/ Kb )
proof
assume A29: f . r in Kb ; :: thesis: d1 . r in K0 \/ Kb
then A30: h . (f . r) = f . r by A2;
d1 . r = h . (f . r) by A3, FUNCT_1:23;
hence d1 . r in K0 \/ Kb by A29, A30, XBOOLE_0:def 3; :: thesis: verum
end;
g . r in rng g by A4, FUNCT_1:12;
then A31: not g . r in K0 by A1, XBOOLE_0:def 4;
A32: ( not g . r in Kb implies d2 . r in K0 \/ Kb )
proof
assume not g . r in Kb ; :: thesis: d2 . r in K0 \/ Kb
then not g . r in K0 \/ Kb by A31, XBOOLE_0:def 3;
then A33: h . (g . r) in K0 by A2;
d2 . r = h . (g . r) by A4, FUNCT_1:23;
hence d2 . r in K0 \/ Kb by A33, XBOOLE_0:def 3; :: thesis: verum
end;
A34: ( g . r in Kb implies d2 . r in K0 \/ Kb )
proof
assume A35: g . r in Kb ; :: thesis: d2 . r in K0 \/ Kb
then A36: h . (g . r) = g . r by A2;
d2 . r = h . (g . r) by A4, FUNCT_1:23;
hence d2 . r in K0 \/ Kb by A35, A36, XBOOLE_0:def 3; :: thesis: verum
end;
now
per cases ( ( d1 . r in K0 & d2 . r in K0 ) or ( d1 . r in K0 & d2 . r in Kb ) or ( d1 . r in Kb & d2 . r in K0 ) or ( d1 . r in Kb & d2 . r in Kb ) ) by A26, A28, A32, A34, XBOOLE_0:def 3;
case A37: ( d1 . r in K0 & d2 . r in K0 ) ; :: thesis: ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
then consider p being Point of (TOP-REAL 2) such that
A38: ( p = d1 . r & - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) by A1;
consider q being Point of (TOP-REAL 2) such that
A39: ( q = d2 . r & - 1 < q `1 & q `1 < 1 & - 1 < q `2 & q `2 < 1 ) by A1, A37;
thus ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 ) by A38, A39; :: thesis: verum
end;
case A40: ( d1 . r in K0 & d2 . r in Kb ) ; :: thesis: ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
then consider p being Point of (TOP-REAL 2) such that
A41: ( p = d1 . r & - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) by A1;
consider q being Point of (TOP-REAL 2) such that
A42: ( q = d2 . r & ( ( - 1 = q `1 & - 1 <= q `2 & q `2 <= 1 ) or ( q `1 = 1 & - 1 <= q `2 & q `2 <= 1 ) or ( - 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) or ( 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) ) ) by A40;
thus ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 ) by A41, A42; :: thesis: verum
end;
case A43: ( d1 . r in Kb & d2 . r in K0 ) ; :: thesis: ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
then consider p being Point of (TOP-REAL 2) such that
A44: ( p = d2 . r & - 1 < p `1 & p `1 < 1 & - 1 < p `2 & p `2 < 1 ) by A1;
consider q being Point of (TOP-REAL 2) such that
A45: ( q = d1 . r & ( ( - 1 = q `1 & - 1 <= q `2 & q `2 <= 1 ) or ( q `1 = 1 & - 1 <= q `2 & q `2 <= 1 ) or ( - 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) or ( 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) ) ) by A43;
thus ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 ) by A44, A45; :: thesis: verum
end;
case A46: ( d1 . r in Kb & d2 . r in Kb ) ; :: thesis: ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 )
then consider p being Point of (TOP-REAL 2) such that
A47: ( p = d2 . r & ( ( - 1 = p `1 & - 1 <= p `2 & p `2 <= 1 ) or ( p `1 = 1 & - 1 <= p `2 & p `2 <= 1 ) or ( - 1 = p `2 & - 1 <= p `1 & p `1 <= 1 ) or ( 1 = p `2 & - 1 <= p `1 & p `1 <= 1 ) ) ) ;
consider q being Point of (TOP-REAL 2) such that
A48: ( q = d1 . r & ( ( - 1 = q `1 & - 1 <= q `2 & q `2 <= 1 ) or ( q `1 = 1 & - 1 <= q `2 & q `2 <= 1 ) or ( - 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) or ( 1 = q `2 & - 1 <= q `1 & q `1 <= 1 ) ) ) by A46;
thus ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 ) by A47, A48; :: thesis: verum
end;
end;
end;
hence ( - 1 <= (d1 . r) `1 & (d1 . r) `1 <= 1 & - 1 <= (d2 . r) `1 & (d2 . r) `1 <= 1 & - 1 <= (d1 . r) `2 & (d1 . r) `2 <= 1 & - 1 <= (d2 . r) `2 & (d2 . r) `2 <= 1 ) ; :: thesis: verum
end;
then rng d1 meets rng d2 by A1, A8, A13, A16, A20, A24, JGRAPH_1:65;
then A49: (rng d1) /\ (rng d2) <> {} by XBOOLE_0:def 7;
consider s being Element of (rng d1) /\ (rng d2);
A50: ( s in rng d1 & s in rng d2 ) by A49, XBOOLE_0:def 4;
then consider t1 being set such that
A51: ( t1 in dom d1 & s = d1 . t1 ) by FUNCT_1:def 5;
consider t2 being set such that
A52: ( t2 in dom d2 & s = d2 . t2 ) by A50, FUNCT_1:def 5;
reconsider W = B ` as non empty Subset of (TOP-REAL 2) by Th19;
A53: the carrier of ((TOP-REAL 2) | W) <> {} ;
h . (f . t1) = d1 . t1 by A51, FUNCT_1:22;
then A54: h . (f . t1) = h . (g . t2) by A51, A52, FUNCT_1:22;
A55: dom h = the carrier of ((TOP-REAL 2) | (B ` )) by A53, FUNCT_2:def 1;
A56: f . t1 in rng f by A3, A51, FUNCT_1:12;
dom g = the carrier of I[01] by FUNCT_2:def 1;
then A57: g . t2 in rng g by A52, FUNCT_1:12;
then f . t1 = g . t2 by A2, A12, A19, A54, A55, A56, FUNCT_1:def 8;
then (rng f) /\ (rng g) <> {} by A56, A57, XBOOLE_0:def 4;
hence rng f meets rng g by XBOOLE_0:def 7; :: thesis: verum