#pragma once
class ast;
bool lt(ast * n1, ast * n2);
bool is_sorted(unsigned num, expr * const * ns);
struct ast_to_lt {
bool operator()(ast * n1, ast * n2) const { return lt(n1, n2); }
};
struct ast_lt {
bool operator()(ast * n1, ast * n2) const { return n1->get_id() < n2->get_id(); }
};
bool lex_lt(unsigned num, ast * const * n1, ast * const * n2);
inline bool lex_lt(unsigned num, expr * const * n1, expr * const * n2) {
return lex_lt(num, reinterpret_cast<ast*const*>(n1), reinterpret_cast<ast*const*>(n2));
}