ex subs(const lst & ls, const lst & lr, bool no_pattern = false) const;
ex eval_indexed(const basic & i) const;
ex add_indexed(const ex & self, const ex & other) const;
ex subs(const lst & ls, const lst & lr, bool no_pattern = false) const;
ex eval_indexed(const basic & i) const;
ex add_indexed(const ex & self, const ex & other) const;