Recently I was told of the theorem in Euclidean geometry that says the following:
Suppose we have $\angle BAC$ and two isogonal* lines $AM$ and $AN$. If $BM\cap CN=P$ and $BN\cap CM=T$, then $AP$ and $AT$ are isogonal lines.
Is there some common name for this theorem ?
*By isogonal lines I mean lines that are symmetric with respect to angle bisector.