iterator matches { name: 'iterator' };
hasNext(res) matches { name: 'hasNext', result: res };
next matches { name: 'next' };

Main = empty ∨ iterator (hasNext(true) next)* hasNext(false);

iterator(id) matches { name: 'iterator', resultId: id };
hasNext(id, res) matches { name: 'hasNext', result: res, targetId: id };
next(id) matches { name: 'next', targetId: id };

Main = empty ∨ { let id;
    iterator(id)
    (hasNext(id, true) next(id))*
    hasNext(id, false)
};

iterator(id) matches { name: 'iterator', resultId: id };
hasNext(id, res) matches { name: 'hasNext', result: res, targetId: id };
next(id) matches { name: 'next', targetId: id };

Main = empty ∨ { let id; iterator(id)
    (Main | (hasNext(id, true) next(id))* hasNext(id, false))
};

// event types push(val), pop(val), size(s) to be defined

Stack<s> = size(s)* { let val;
    push(val) Stack<s+1> pop(val) Stack<s>
}?;

Main = Stack<0>;

// event types enq(val), deq and deq(val) to be defined

Main = { let val;
    enq(val)
    ((deq | Main ) ∧ ( deq ≫ deq(val) all))
}?;