let a, b, r, s be real number ; :: thesis: ( a <= b & r <= s implies R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):] is Function of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):],(Trectangle a,b,r,s) )
set C1 = Closed-Interval-TSpace a,b;
set C2 = Closed-Interval-TSpace r,s;
set TR = Trectangle a,b,r,s;
set h = R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):];
assume ( a <= b & r <= s ) ; :: thesis: R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):] is Function of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):],(Trectangle a,b,r,s)
then A1: the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):] = [:[.a,b.],[.r,s.]:] by Th48;
dom R2Homeomorphism = [:the carrier of R^1 ,the carrier of R^1 :] by Lm1, FUNCT_2:def 1;
then A2: dom (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) = the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):] by A1, RELAT_1:91, TOPMETR:24, ZFMISC_1:119;
rng (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) c= the carrier of (Trectangle a,b,r,s)
proof
let y be set ; :: according to TARSKI:def 3 :: thesis: ( not y in rng (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) or y in the carrier of (Trectangle a,b,r,s) )
assume y in rng (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) ; :: thesis: y in the carrier of (Trectangle a,b,r,s)
then consider x being set such that
A3: x in dom (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) and
A4: (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) . x = y by FUNCT_1:def 5;
A5: the carrier of (Trectangle a,b,r,s) = closed_inside_of_rectangle a,b,r,s by PRE_TOPC:29;
A6: closed_inside_of_rectangle a,b,r,s = { p where p is Point of (TOP-REAL 2) : ( a <= p `1 & p `1 <= b & r <= p `2 & p `2 <= s ) } by JGRAPH_6:def 2;
reconsider x = x as Point of [:R^1 ,R^1 :] by A3;
A7: (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) . x = R2Homeomorphism . x by A3, FUNCT_1:70;
then reconsider p = (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) . x as Point of (TOP-REAL 2) ;
dom (R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) c= [:the carrier of R^1 ,the carrier of R^1 :] by A1, A2, TOPMETR:24, ZFMISC_1:119;
then consider x1, x2 being Element of the carrier of R^1 such that
A8: x = [x1,x2] by A3, DOMAIN_1:9;
(R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):]) . x = <*x1,x2*> by A7, A8, Def2;
then A9: ( x1 = p `1 & x2 = p `2 ) by FINSEQ_1:61;
( x1 in [.a,b.] & x2 in [.r,s.] ) by A1, A2, A3, A8, ZFMISC_1:106;
then ( a <= p `1 & p `1 <= b & r <= p `2 & p `2 <= s ) by A9, XXREAL_1:1;
hence y in the carrier of (Trectangle a,b,r,s) by A4, A5, A6; :: thesis: verum
end;
hence R2Homeomorphism | the carrier of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):] is Function of [:(Closed-Interval-TSpace a,b),(Closed-Interval-TSpace r,s):],(Trectangle a,b,r,s) by A2, FUNCT_2:4; :: thesis: verum