HARDY Diagrams

Diagrams consist of nodes and arcs. This may
seem limiting, but it is surprising how many
types of diagram can fit into this framework.

Before editing a diagram, it is necessary to have 
available a diagram type, which specifies what
kind of nodes and arcs a diagram can have,
and what their shapes, colours and characteristics
are. A diagram type may be supplied for you, or
you may wish to create your own.

When you have edited a diagram, you may print it
out or save it in Prolog, LISP or CLIPS form,
perhaps for processing by another program.
