List_cells = [];
for i=1:length(GLOBAL_PIHA.Cells)
   NOT_END    = 1 ;
   j          = 1 ;
   while NOT_END
      ADD =1;
     	if (compvec(GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{i}.boundary(j)}.c,[0 0 1])|...
     	    compvec(GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{i}.boundary(j)}.c,[0 0 -1]))&...
       	(GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{i}.boundary(j)}.pthb ==-1)
     		NOT_END = 0;
     		ADD = 0;
     	elseif (j==length(GLOBAL_PIHA.Cells{i}.boundary))
         NOT_END = 0;
      else
      	j = j+1;      
      end
   end
   if ADD
      List_cells = [ List_cells i];
   end
end
counter = 1;
   for i=1:length(List_cells)
   	V_C = [];
   	V_d = [];
   	for j=1:length(GLOBAL_PIHA.Cells{List_cells(i)}.boundary)
      	if compvec(GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j)}.c,[0 0 1])
            V_C = V_C;
            V_d = V_d;
         else
					if GLOBAL_PIHA.Cells{List_cells(i)}.hpflags(GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j))
						V_C =[V_C;GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j)}.c];
                  V_d =[V_d;GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j)}.d];
               else
                  V_C =[V_C;-GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j)}.c];
                  V_d =[V_d;-GLOBAL_PIHA.Hyperplanes{GLOBAL_PIHA.Cells{List_cells(i)}.boundary(j)}.d];
					end
      	end
      end
      new_cell(i)= linearcon([0 0 1],0,V_C,V_d);
   end