assume [P,A,L,B,C] : (plane(P) & point(A) & line(L) & point(B) & point(C) & ninc_po_pl(A,P) & inc_po_l(A,L) & inc_po_l(B,L) & inc_po_l(C,L) & inc_po_pl(B,P) & inc_po_pl(C,P))
have (B = C)
