1 #define noargs() 1 2 # define onearg(foo) foo 3 # define twoargs( x , y ) x y 4 # define threeargs( a , b , c ) a b c 5 noargs ( ) 6 onearg ( 2 ) 7 twoargs ( 3 , 4 ) 8 threeargs ( 5 , 6 , 7 ) 9