theorem Th19: :: ANPROJ_8:22

for M being Matrix of 3,F_Real
for p1, p2, p3, q1, q2, q3, r1, r2, r3 being Real st M = <*<*p1,q1,r1*>,<*p2,q2,r2*>,<*p3,q3,r3*>*> holds
M @ = <*<*p1,p2,p3*>,<*q1,q2,q3*>,<*r1,r2,r3*>*>