:: deftheorem defines is_congruent_Matrix_of MATRIX_8:def 6 :
for n being Nat
for K being Field
for M1, M2 being Matrix of n,K holds
( M1 is_congruent_Matrix_of M2 iff ex M being Matrix of n,K st
( M is invertible & M1 = ((M @) * M2) * M ) );