theorem Th36:
  AcyclicPaths(p) c= AcyclicPaths(G)
proof
  let e be object;
  assume e in AcyclicPaths(p);
  then ex q being Simple oriented Chain of G st ( e=q)&( q <> {} )&( (the
Source of G).(q.1) = (the Source of G).(p.1))&( (the Target of G).(q.( len q))
  = (the Target of G).(p.(len p)))&( rng q c= rng p);
  hence thesis;
end;
