Lehmus's Theorem

Lehmus:=proc() local N,M,m,n,T,A,B,C:

T:= Te(m,n):    A:=T[1]:    B:=T[2]:    C:=T[3]:

N:= Pt ( LePtSlope (A, TS (m,m))    ,    LePtSlope (B,-n)):

M:= Pt (LePtSlope(A,m))    ,    LePtSlope (B, TS(-n,-n))):

ItIsZero (subs(m=n,factor( DeSq (B,N) -  DeSq(A,M)))):

end: