(1-log3 18)*(1-log6 18)=(log3 3-log3 18)*( log6 6-log6 18)=
=log3(3/18)*log6(6/18)=log3(1/6)*log6(1/3)=log3(1/6)*(log3(1/3))/log36=
=-log36*(-1/log36)=1
(1-log3 18)*(1-log6 18)=(log3 3-log3 18)*( log6 6-log6 18)=
=log3(3/18)*log6(6/18)=log3(1/6)*log6(1/3)=log3(1/6)*(log3(1/3))/log36=
=-log36*(-1/log36)=1