ex subs(const lst & ls, const lst & lr) const;
exvector get_indices(void) const;
ex thisexprseq(const exvector & v) const;
ex thisexprseq(exvector * vp) const;
protected:
ex subs(const lst & ls, const lst & lr) const;
exvector get_indices(void) const;
ex thisexprseq(const exvector & v) const;
ex thisexprseq(exvector * vp) const;
protected: