u := 1cm; pair p[]; beginfig(1) p0 = (1u, 0u); p1 = (1u, 2u); p2 = (0u, 2u); p3 = (0u, 0u); p4 = (0u, 1u); draw p2--p1--p0; draw p3--p4; for i=0 upto 4: draw p[i] withpen pencircle scaled .15u;endfor; endfig; end;