data _null_;
if 0 then set have(rename=(var=_var));
if _n_=1 then do;
declare hash h(dataset:'have(rename=(var=_var))',ordered:'a');
h.definekey('_var');
h.definedata('_var');
h.definedone();
declare hiter hi ('h');
end;
set have1 end=last;
h.find(key:var);
do rc=hi.next() by 0 while (rc=0);
if findc(compress(_var),compress(var))=0 then do;
_var=cats(var,_var);
h.ref();
end;
rc=hi.next();
end;
if last then h.output(dataset:'want(rename=_var=var)');
run;