#ifndef MATH_ITERATOR_H
#define MATH_ITERATOR_H
+
#include "math_pos.h"
#include <vector>
using base_type::back;
using base_type::begin;
using base_type::end;
+ using base_type::erase;
using base_type::operator[];
using base_type::size_type;
using base_type::difference_type;
void goEnd();
/// read access to top most item
MathArray const & cell() const;
+ /// is this a non-end position
+ bool normal() const;
+ /// shrinks to at most i levels
+ void shrink(size_type i);
private:
/// own level down