AGG provides the possibility to formulate consistency conditions
which can be tested on single graphs,
but which can also be shown for a whole graph transformation system.
Herewith we have in AGG a consistency control mechanism which is able to
check certain consistency conditions for a given graph.
Generally,
consistency conditions (CC) describe basic (global) properties
of graphs as e.g. the existence of certain elements,
independent of a particular rule.
But we also provide a transformation of global consistency conditions into
post application conditions for individual rules. A so-constructed rule
is applicable to a consistent graph if and only if the derived graph is
consistent, too. A graph grammar is consistent, if the start graph satisfies
consistency conditions and the rules preserve this property.
If a consistency condition holds for a graph transformations system,
all derived graphs satisfy this condition.
Consistency of conditional graph grammars is described in: