  The symmetric group on 4 letters has the reflection group $D_{3}$ as an
isomorphic image. This fact follows from the coincidence of the root systems
$A_{3}$ and $D_{3}$. The isomorphism is used to construct an orthogonal basis
of polynomials of 4 variables with 2 parameters. There is an associated quantum
Calogero-Sutherland model of 4 identical particles on the line.
