YFlang

//Church number
function zero=(function f, int s)->{return f(s);};
function inc_1=(function m, function f, int s)->{return (function f, int s)->{return f(m (f, s));};};
function add_2=(function m, function n, function f, int s)->{return (function f, int s)->{return m (f (n (f (s))));};};
function f; int s;
//1=0'
function n_1=inc_1(zero, f, s);
//2=1+1=0'+0'
function n_2=add_2(n_1, n_1, f, s);

//class, generic, hierarchy
class A<T1>{
T1 a;
T1 f(T1 a){this.a=a; return new T1();}
}

class B<T1> extends A{
T1 b;
<T2> T2 g(){return new T2();}
}

A<int> b=new B<int>();
int i=b.f(1);
bool j=((B<int>)b).<bool>g();