1 #define x y
2 #define x z
3 
4 #define abc 123
5 #define abc() 123
6 
7 #define foo() bar
8 #define foo(x) bar
9 
10 #define bar() baz
11 #define bar baz
12 
13 #define biff(a,b) a+b
14 #define biff(a,b,c) a+b
15 
16 #define oper(a,b) a+b
17 #define oper(a,b) a*b
18