let a, b, r be Real; r (#) (AffineMap (a,b)) = AffineMap ((r * a),(r * b))
D1:
dom (r (#) (AffineMap (a,b))) = REAL
by FUNCT_2:def 1;
D2:
REAL = dom (AffineMap ((r * a),(r * b)))
by FUNCT_2:def 1;
for x being object st x in dom (AffineMap ((r * a),(r * b))) holds
(r (#) (AffineMap (a,b))) . x = (AffineMap ((r * a),(r * b))) . x
proof
let x be
object ;
( x in dom (AffineMap ((r * a),(r * b))) implies (r (#) (AffineMap (a,b))) . x = (AffineMap ((r * a),(r * b))) . x )
assume
x in dom (AffineMap ((r * a),(r * b)))
;
(r (#) (AffineMap (a,b))) . x = (AffineMap ((r * a),(r * b))) . x
then reconsider x =
x as
Real ;
(r (#) (AffineMap (a,b))) . x =
r * ((AffineMap (a,b)) . x)
by VALUED_1:6
.=
r * ((a * x) + b)
by FCONT_1:def 4
.=
((r * a) * x) + (r * b)
.=
(AffineMap ((r * a),(r * b))) . x
by FCONT_1:def 4
;
hence
(r (#) (AffineMap (a,b))) . x = (AffineMap ((r * a),(r * b))) . x
;
verum
end;
hence
r (#) (AffineMap (a,b)) = AffineMap ((r * a),(r * b))
by FUNCT_1:2, D1, D2; verum