theorem :: GLIB_012:34

for G3 being _Graph
for E, V being set
for G4 being reverseEdgeDirections of G3,E
for G1 being addLoops of G3,V
for G2 being reverseEdgeDirections of G1,E st E c= the_Edges_of G3 holds
G2 is addLoops of G4,V