theorem Th98: :: GLIBPRE0:92

for G1, G2 being _Graph
for F being PGraphMapping of G1,G2
for v being Vertex of G1 st F is Disomorphism holds
( v .inDegree() = ((F _V) /. v) .inDegree() & v .outDegree() = ((F _V) /. v) .outDegree() )