13-5 gyrochoron

The 13-5 gyrochoron, also known as the tridecachoron, is a convex isochoric polychoron and member of the gyrochoron family with 13 elongated gyrobifastigia as cells. It is also the pentagonal funk prism.

Each cell of this polychoron has BC2+×A1+ symmetry, with 4 pentagonal and 4 tetragonal faces.

Compared to other gyrochora with 13 cells, this polychoron has doubled symmetry, because 13 is a factor of 52+1 = 26.

Isogonal derivatives
Substitution by vertices of these following elements will produce these convex isogonal polychora:
 * Elongated gyrobifastigium (13): 13-5 step prism
 * Mirror-symmetric pentagon (26): Small 13-5 double gyrostep prism
 * Kite (26): Small 13-5 double step prism
 * Vertex (13): 13-5 step prism