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