ex coeff(const ex & s, int n = 1) const;
ex eval(int level=0) const;
ex evalf(int level=0) const;
+ ex evalm(void) const;
ex series(const relational & s, int order, unsigned options = 0) const;
ex subs(const lst & ls, const lst & lr, bool no_pattern = false) const;
ex normal(lst &sym_lst, lst &repl_lst, int level = 0) const;