
theorem
  for G being _finite _Graph, S being VertexScheme of G holds len S =
  card the_Vertices_of G
proof
  let G be _finite _Graph, S be VertexScheme of G;
A1: S is one-to-one by Def12;
  rng S = the_Vertices_of G by Def12;
  hence thesis by A1,FINSEQ_4:62;
end;
