theorem Th15:
for
X,
Y,
Z being
RealNormSpace ex
I being
Function of
[:X,Y,Z:],
(product <*X,Y,Z*>) st
(
I is
one-to-one &
I is
onto & ( for
x being
Point of
X for
y being
Point of
Y for
z being
Point of
Z holds
I . (
x,
y,
z)
= <*x,y,z*> ) & ( for
v,
w being
Point of
[:X,Y,Z:] holds
I . (v + w) = (I . v) + (I . w) ) & ( for
v being
Point of
[:X,Y,Z:] for
r being
Real holds
I . (r * v) = r * (I . v) ) &
0. (product <*X,Y,Z*>) = I . (0. [:X,Y,Z:]) & ( for
v being
Point of
[:X,Y,Z:] holds
||.(I . v).|| = ||.v.|| ) )