--  FILE   EXA.RIG
--  This example illustrates how to program
-- TAIL and HEAD functions in RIGAL.
#MAIN
 $E:= (. ALFA BETA GAMMA DELTA LAMBDA .) ; 
 PRINT $E;
 PRINT #HEAD($E);
 PRINT #TAIL($E);
##

#HEAD
 (. $E   (*  $A *) .)   / RETURN $E / ##
#TAIL
 (. $A   (* $L !.:= $E *) .) / RETURN $L / ##