theorem Th12:
for
X,
Y being
RealLinearSpace ex
I being
Function of
[:X,Y:],
(product <*X,Y*>) st
(
I is
one-to-one &
I is
onto & ( for
x being
Point of
X for
y being
Point of
Y holds
I . (
x,
y)
= <*x,y*> ) & ( for
v,
w being
Point of
[:X,Y:] holds
I . (v + w) = (I . v) + (I . w) ) & ( for
v being
Point of
[:X,Y:] for
r being
Real holds
I . (r * v) = r * (I . v) ) &
I . (0. [:X,Y:]) = 0. (product <*X,Y*>) )