"
 Sorry, but there is no ""network"" for ""Ecoles polytechniques"", contrary to Ecoles centrales or Ecoles des mines. The word ""polytechnique"" is very misleading !
 The categories ""Ecoles nationales supérieures"" or ""Ecoles supérieures"" are irrelevant ! You have put in the same category institutions which have nothing to do together ! It was a capharnaüm !   "