Check whether next column is same as current

data sandbox.&domain._deriv(drop = var x y i);
  merge &domain._: ;
  by var;

  array chars [*] _character_;
  x =0;
  y= 0;


  do i= 1 to dim(chars)-1;
    if chars{i} ne chars{i+1} then do;
    x + 1;
    end;
  end;


  if x ne 0 then output;
run;