Amallamorphic graphs

Amallamorphic graphs --- амалламорфные графы.

Let [math]\displaystyle{ M }[/math] be a multigraph. Let [math]\displaystyle{ G(M) }[/math] denote a graph obtained from [math]\displaystyle{ M }[/math] by replacing every multiple edge by a simple edge. Two multigraphs [math]\displaystyle{ M_{1} }[/math] and [math]\displaystyle{ M_{2} }[/math] are amallamorphic if [math]\displaystyle{ G(M_{1}) }[/math] is isomorphic to [math]\displaystyle{ G(M_{2}) }[/math].