class Class<T> {}

class ConcreteClass implements Class<ConcreteClass> {}

typedef F<X extends Class<X>> = X;

class G<X extends Class<X>> {}

t1a() {}
t2a() {}
t3a() {}
t4a() {}
t5a() {}
t6a() {}
t7a() {}
t8a() {}
s1a() {}
s2a() {}
s3a() {}
s4a() {}
s5a() {}
s6a() {}
s7a() {}
s8a() {}
t1b() {}
t2b() {}
t3b() {}
t4b() {}
t5b() {}
t6b() {}
t7b() {}
t8b() {}
s1b() {}
s2b() {}
s3b() {}
s4b() {}
s5b() {}
s6b() {}
s7b() {}
s8b() {}
main() {}