Duoantifastegiaprism

A duoantiwedge or duoantifastegiaprism is a class of scaliform polytopes formed in a similar way to antiprisms, where the bases are two congurent duoprisms in opposite orientations. The simplest non-trivial duoantiwedge is the triangular duoantiwedge, which has a triangular duoprism base. The dual of a duoantiwedge is a duoantinotch. The duoprism-first envelope of a duoantiwedge is a duoantiprism.

If one of the polytopes is a dyad, then the resulting polytope is a duoantifastegium made out of two congurent prisms in opposite orientations, with the simplest example being the digonal-triangular duoantiwedge. If both polytopes are dyads, then the resulting polytope is the square disphenoid, which cannot be made scaliform, as the height would be 0 if all edges were equal.