tex macro for input separated by whitespace

%for more generic length control to the following command, see:
%https://tex.stackexchange.com/questions/12810/how-do-i-split-a-string

\def\orderit#1{\ordersep#1\relax}
\def\ordersep#1 #2 #3 #4\relax{\scriptstyle #1<_\sigma #2 <_\sigma #3 <_\sigma #4}