theorem Th109:
for
m,
n being
Nat for
K being
Field for
M being
Matrix of
m,
n,
K st
M is
without_repeated_line holds
( ( ( for
i being
Nat st
i in Seg m holds
Line (
M,
i)
<> n |-> (0. K) ) & ( for
M1 being
Matrix of
m,
n,
K st ( for
i being
Nat st
i in Seg m holds
ex
a being
Element of
K st
Line (
M1,
i)
= a * (Line (M,i)) ) & ( for
j being
Nat st
j in Seg n holds
Sum (Col (M1,j)) = 0. K ) holds
M1 = 0. (
K,
m,
n) ) ) iff
lines M is
linearly-independent )