input geom2d; beginfig(1); F1 = Point(-2,1); F2 = Point(2,-1); E1 = EllipseF(F1,F2,2.5); E2 = EllipseF(F1,F2,4); Dir = Directrix(E1,1); H1 = HyperbolaF(F1,F2,1.9); H2 = HyperbolaF(F1,F2,1.1); s1H1 = Chemin(SemiHyperbola(H1,1)); s2H1 = Chemin(SemiHyperbola(H1,2)); s1H2 = Chemin(SemiHyperbola(H2,1)); s2H2 = Chemin(SemiHyperbola(H2,2)); gddDraw E1; gddDraw E2; gddDraw s1H1; gddDraw s2H1; gddDraw s1H2; gddDraw s2H2; P1 = IntersectionPoint(E1,s1H1); P2 = IntersectionPoint(E2,s1H1); P3 = IntersectionPoint(E1,s1H2); P4 = IntersectionPoint(E2,s1H2); P14 = Segment(P1,P4); P23 = Segment(P2,P3); gddDraw P14; gddDraw P23; gddDraw LineMark(P14,1); gddDraw LineMark(P23,1); gddDrawPoint F1; gddDrawPoint F2; gddMark.urt "P1"; gddMark.urt "P2"; gddMark.urt "P3"; gddMark.urt "P4"; Window(-6,-6,6,6); endfig; end