theorem Th2:
for
V being
RealLinearSpace for
u,
v,
u1,
v1 being
Element of
V st ( for
a,
b,
a1,
b1 being
Real st
(((a * u) + (b * v)) + (a1 * u1)) + (b1 * v1) = 0. V holds
(
a = 0 &
b = 0 &
a1 = 0 &
b1 = 0 ) ) holds
( not
u is
zero & not
v is
zero & not
are_Prop u,
v & not
u1 is
zero & not
v1 is
zero & not
are_Prop u1,
v1 & not
u,
v,
u1 are_LinDep & not
u1,
v1,
u are_LinDep )