:: deftheorem Def31 defines .edgesDBetween GLIB_000:def 31 :
for G being _Graph
for X, Y being set
for b₄ being Subset of (the_Edges_of G) holds
( b₄ = G .edgesDBetween (X,Y) iff for e being object holds
( e in b₄ iff e DSJoins X,Y,G ) );