theorem Th31: :: MATRIX11:31
for n being Nat
for K being commutative Ring
for a, b being Element of K
for l being Nat
for pK, qK being FinSequence of K
for perm being Element of Permutations n st l in Seg n & len pK = n & len qK = n holds
for M being Matrix of n,K holds the multF of K $$ (Path_matrix (perm,(RLine (M,l,((a * pK) + (b * qK)))))) = (a * ( the multF of K $$ (Path_matrix (perm,(RLine (M,l,pK)))))) + (b * ( the multF of K $$ (Path_matrix (perm,(RLine (M,l,qK))))))