theorem Th14: :: MATRIX15:14
for K being Field
for V being VectSp of K
for U being finite Subset of V
for u, v being Vector of V
for a being Element of K st u in U & v in U & ( not u = v or a <> - (1_ K) or u = 0. V ) holds
Lin ((U \ {u}) \/ {(u + (a * v))}) = Lin U