data pairs_dstep;
  set sashelp.class(keep=Name Age);
  do i=1 to Subjects;
    set sashelp.class(keep=Name Age rename=(Name=NameOlder Age=AgeOlder))
          nobs=Subjects point=i;
    if Age lt AgeOlder then output;
  end;
run;
proc sort data=pairs_dstep;
  by Age AgeOlder Name NameOlder;
run;
proc print data=pairs_dstep(obs=20);
  by Age AgeOlder;
  id Age AgeOlder;
  title1 "Student Mentor Pairings";
run;