theorem Th18:
  |.Kv.| c= [#]Kv implies [#]BCS(n,Kv) = [#]Kv
 proof
  assume|.Kv.|c=[#]Kv;
  then BCS(n,Kv)=subdivision(n,center_of_mass V,Kv) by Def6;
  hence thesis by SIMPLEX0:64;
 end;
