let V be non empty set ; for E being symmetric Relation of V
for G being GraphFromSymRel of V,E
for X, Y being set holds G .edgesBetween (X,Y) c= ((Y |` E) | X) \/ ((X |` E) | Y)
let E be symmetric Relation of V; for G being GraphFromSymRel of V,E
for X, Y being set holds G .edgesBetween (X,Y) c= ((Y |` E) | X) \/ ((X |` E) | Y)
let G be GraphFromSymRel of V,E; for X, Y being set holds G .edgesBetween (X,Y) c= ((Y |` E) | X) \/ ((X |` E) | Y)
let X, Y be set ; G .edgesBetween (X,Y) c= ((Y |` E) | X) \/ ((X |` E) | Y)
((Y |` E) | X) \/ ((X |` E) | Y) = (createGraph (V,E)) .edgesBetween (X,Y)
by Th77;
hence
G .edgesBetween (X,Y) c= ((Y |` E) | X) \/ ((X |` E) | Y)
by GLIB_000:77; verum