:: deftheorem defines * GLIB_010:def 34 :
for G1, G2, G3 being _Graph
for F1 being PGraphMapping of G1,G2
for F2 being PGraphMapping of G2,G3 holds F2 * F1 = [((F2 _V) * (F1 _V)),((F2 _E) * (F1 _E))];