:: deftheorem Def8 defines .componentSet() GLIB_002:def 8 :
for G being _Graph
for b₂ being non empty Subset-Family of (the_Vertices_of G) holds
( b₂ = G .componentSet() iff for x being set holds
( x in b₂ iff ex v being Vertex of G st x = G .reachableFrom v ) );