1import "B.if"
2import "types.if"
3
4package a {
5    interface A {
6        types.int x;
7	    -> A self;    // this "self" variable must be the same as "other" of "B"
8	    -> b.B other; // this "other" variable must be the same as "self" of "B"
9    }
10}
11