for G1, G2 being _Graph
for F being semi-Dcontinuous PGraphMapping of G1,G2 st ( for v being object st v in dom (F _V) holds
ex e, w being object st
( e in dom (F _E) & w in dom (F _V) & (F _E) . e DJoins (F _V) . v,(F _V) . w,G2 ) ) holds
F _V is one-to-one