# Pappus Theorem
Let(A=[x1,0], B=[x2,0], C=[x3,0], A1=[0,x4], B1=[0,x5], C1=[0,x6],
    P1=[x7,x8], P2=[x9,x10], P3=[x11,x12]):
Pappus := Theorem(
    [arbitrary(A,B,C,A1,B1,C1), collinear(A,B,C), collinear(A1,B1,C1),
     intersection(A,B1,A1,B,P1), intersection(A,C1,A1,C,P2),
     intersection(B,C1,B1,C,P3)], collinear(P1,P2,P3),
    [x7,x8,x9,x10,x11,x12]);
