Base class for forward rules. Holds a head pattern (which will
be matched against the triple store) and an array of body patterns.
The body patterns can be instantiated following a successful head
match and then processed be descendant class.
author: Dave Reynolds version: $Revision: 1.10 $ on $Date: 2008/01/02 12:06:43 $
Assistant method to parse a string into a sequence oftriple patterns.
The patterns may be separated by "<-", "->" or "|" strings.
a list of TriplePatterns