2OVER 2LITERAL 2R>
2OVER ( a,a b,b -- a,a b,b a,a )  
ansi .6.1.0400 <CORE>
double-cell over, see OVER and 2DUP 
 simulate:
   : 2OVER SP@ 2 CELLS + 2@ ;

reference: p4_two_over in ../src/core.c:0460, export CO 2OVER