# Steiner-Lehmus Theorem
Let(A=[-1,0], B=[1,0], C=[x1,x2], A1=[x3,x4], B1=[x5,x6]):
SteinerLehmus := Theorem(
    [arbitrary(A,B,C), equiangle(C,A,A1,A1,A,B), equiangle(A,B,B1,B1,B,C),
     online(B1,A,C), online(A1,B,C), equidistance(A,A1,B,B1)],
    equidistance(A,C,B,C), [x1,x2,x3,x4,x5,x6]);
