let a, b be real number ; :: thesis: ( a < b implies ( id (Closed-Interval-TSpace a,b) = (L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) & id (Closed-Interval-TSpace 0 ,1) = (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b)) ) )
A1: ( 0 = (#) 0 ,1 & 1 = 0 ,1 (#) ) by Def1, Def2;
set L = L[01] (a,b (#) ),((#) a,b);
set P = P[01] a,b,(0 ,1 (#) ),((#) 0 ,1);
assume A2: a < b ; :: thesis: ( id (Closed-Interval-TSpace a,b) = (L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) & id (Closed-Interval-TSpace 0 ,1) = (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b)) )
then A3: b - a <> 0 ;
A4: ( a = (#) a,b & b = a,b (#) ) by A2, Def1, Def2;
for c being Point of (Closed-Interval-TSpace a,b) holds ((L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1))) . c = c
proof
let c be Point of (Closed-Interval-TSpace a,b); :: thesis: ((L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1))) . c = c
reconsider r = c as Real by A2, Lm2;
A5: (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) . c = (((b - r) * 1) + ((r - a) * 0 )) / (b - a) by A2, A1, Def4
.= (b - r) / (b - a) ;
thus ((L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1))) . c = (L[01] (a,b (#) ),((#) a,b)) . ((P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) . c) by FUNCT_2:21
.= ((1 - ((b - r) / (b - a))) * b) + (((b - r) / (b - a)) * a) by A2, A4, A5, Def3
.= ((((1 * (b - a)) - (b - r)) / (b - a)) * b) + (((b - r) / (b - a)) * a) by A3, XCMPLX_1:128
.= (((r - a) / (b - a)) * (b / 1)) + (((b - r) / (b - a)) * a)
.= (((r - a) * b) / (1 * (b - a))) + (((b - r) / (b - a)) * a) by XCMPLX_1:77
.= (((r - a) * b) / (b - a)) + (((b - r) / (b - a)) * (a / 1))
.= (((r - a) * b) / (b - a)) + (((b - r) * a) / (1 * (b - a))) by XCMPLX_1:77
.= (((b * r) - (b * a)) + ((b - r) * a)) / (b - a) by XCMPLX_1:63
.= ((b - a) * r) / (b - a)
.= c by A3, XCMPLX_1:90 ; :: thesis: verum
end;
hence id (Closed-Interval-TSpace a,b) = (L[01] (a,b (#) ),((#) a,b)) * (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) by TMAP_1:92; :: thesis: id (Closed-Interval-TSpace 0 ,1) = (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b))
for c being Point of (Closed-Interval-TSpace 0 ,1) holds ((P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b))) . c = c
proof
let c be Point of (Closed-Interval-TSpace 0 ,1); :: thesis: ((P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b))) . c = c
reconsider r = c as Real by Lm2;
A6: (L[01] (a,b (#) ),((#) a,b)) . c = ((1 - r) * b) + (r * a) by A2, A4, Def3
.= (r * (a - b)) + b ;
thus ((P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b))) . c = (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) . ((L[01] (a,b (#) ),((#) a,b)) . c) by FUNCT_2:21
.= (((b - ((r * (a - b)) + b)) * 1) + ((((r * (a - b)) + b) - a) * 0 )) / (b - a) by A2, A1, A6, Def4
.= (r * (- (a - b))) / (b - a)
.= c by A3, XCMPLX_1:90 ; :: thesis: verum
end;
hence id (Closed-Interval-TSpace 0 ,1) = (P[01] a,b,(0 ,1 (#) ),((#) 0 ,1)) * (L[01] (a,b (#) ),((#) a,b)) by TMAP_1:92; :: thesis: verum