:: deftheorem Def2 defines has_valid_flow_from GLIB_005:def 2 :
for G being _finite real-weighted WGraph
for EL being FF:ELabeling of G
for source, sink being set holds
( EL has_valid_flow_from source,sink iff ( source is Vertex of G & sink is Vertex of G & ( for e being set st e in the_Edges_of G holds
( 0 <= EL . e & EL . e <= (the_Weight_of G) . e ) ) & ( for v being Vertex of G st v <> source & v <> sink holds
Sum (EL | (v .edgesIn())) = Sum (EL | (v .edgesOut())) ) ) );