Graph transformation rule

Graph transformation rule --- правило преобразования графа.

A graph transformation rule [math]\displaystyle{ r: \; L \rightarrow R }[/math] is a partial graph morphism from [math]\displaystyle{ L }[/math], the left-hand side, to [math]\displaystyle{ R }[/math], the right-hand side of the rule [math]\displaystyle{ r }[/math]. A redex of [math]\displaystyle{ r }[/math] in a graph [math]\displaystyle{ G }[/math] is a total graph morphism [math]\displaystyle{ m: \; L \rightarrow G }[/math] from the left-hand side of the rule to [math]\displaystyle{ G }[/math].