1@protocol Foo
2- (void)foo;
3@end
4
5@interface Foo_c <Foo>
6{
7}
8- (void)foo;
9@end
10
11@implementation Foo_c
12- (void)foo
13{
14}
15@end
16
17int main (void)
18{
19  return 0;
20}
21
22