This section describes how graphs can be constructed and manipulated
by . provides two kinds of graph rewrite systems for this:
edge addition rewrite systems (EARS) and general terminating
exhaustive graph rewrite systems (XGRS, GRS).
EARS are equivalent to with binary predicates [CGT89b]
[CGT89a] [Aßm94] [Aßm95], and their rules
may be written in this style (similar to Prolog clauses).
In rule tests (rule bodies) are rule right hand sides.
In graph rewrite rules rule tests form left hand sides.
In order to avoid confusion we will denote the left hand side of GRS
rules and the right hand side of rules with the term rule
test.
We will denote the right hand side of GRS rules and the left hand
sides of rules by rule transformation.