theorem Th14: :: BKMODEL4:23

for N being invertible Matrix of 3,F_Real st N = <*<*(2 / 3),0,(- (1 / 3))*>,<*0,(1 / (sqrt 3)),0*>,<*(1 / 3),0,(- (2 / 3))*>*> holds
(homography N) .: absolute c= absolute