for G1, G2 being _Graph
for f being PartFunc of (the_Vertices_of G1),(the_Vertices_of G2)
for g being PartFunc of (the_Edges_of G1),(the_Edges_of G2) st ( for e being object st e in dom g holds
( (the_Source_of G1) . e in dom f & (the_Target_of G1) . e in dom f ) ) & ( for e, v, w being object st e in dom g & v in dom f & w in dom f holds
( e DJoins v,w,G1 iff g . e DJoins f . v,f . w,G2 ) ) holds
[f,g] is semi-Dcontinuous PGraphMapping of G1,G2