theorem :: GLIBPRE0:53

for G1 being _Graph
for G2 being reverseEdgeDirections of G1
for v1 being Vertex of G1
for v2 being Vertex of G2 st v1 = v2 holds
( v2 .edgesIn() = v1 .edgesOut() & v2 .inDegree() = v1 .outDegree() & v2 .edgesOut() = v1 .edgesIn() & v2 .outDegree() = v1 .inDegree() )