fof(goal, conjecture,(![P1,P2,A,L,B,C]:((plane(P1)&plane(P2)&point(A)&line(L)&P1!=P2&inc_po_pl(A,P1)&inc_po_pl(A,P2)&inc_l_pl(L,P1)&inc_l_pl(L,P2)&point(B)&point(C)&B!=C&inc_po_l(B,L)&inc_po_l(C,L)&ninc_po_l(A,L))=>(P1=P2)))).
