52
virtual tetrahedra
As is known, a virtual polytope is
a pair of type (a
closed piecewise linear surface; an associated fan).
For the most of
closed surfaces, there exist no associated fan
(therefore, virtual polytopes are rare phenomena
among closed
piecewise linear surfaces. But this is not the
case for a tetrahedron: there exist 52 different fans
associated with a
tetrahedron. Here they are:
