L(t,P) = Trilinear Polar of triangle t = (ABC) with respect to point P. But t is constructed by errecting isosceli triangles, similar to u=(GHI), on the sides of another triangle s = (DEF). Find the envelope of L(t,P) as the isosceles changes its altitude.

A problem not related to the well known Kiepert Parabola and having a locus which may possess cusps, depending on the location of P and the shape of triangle DEF. Kiepert's Parabola of DEF results as the envelope of trilinear polars L_{P} with respect to DEF, where P is the center of perspective of triangles DEF and ABC (hence L_{p} is their perspective axis).