Problem Statement:
Display and animate a fourbar linkage.
The details for the programs using
QuickAnimation, presented below, are decribed in
Ch Mechanism Toolkit User's Guide 
for
Ch Mechanism Toolkit.
 Animation
Each of these three programs 
fourbar_ani1.ch,
fourbar_ani2.ch, and
fourbar_ani3.ch
uses Ch QuickAnimation for quick animation
of a fourbar linkage as shown below.
 
Display
The program 
fourbar_pos.ch
uses Ch QuickAnimation to display multiple 
a confirguration of a fourbar linkage shown below.
