#pragma once

#include <deque>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <vector>

using namespace std::string_literals;

using BNF = std::map<std::string, std::vector<std::vector<std::string>>>;

std::map<std::string, std::set<std::string>> Reverse(BNF bnf);

BNF SubBNF(const BNF& bnf, const std::string& top);