`var'
-----

var(RAT)
     :: RAT $B$N<gJQ?t(B.

RETURN
     $BITDj85(B

RAT
     $BM-M}<0(B

   * $B<gJQ?t$K4X$7$F$O(B, *Note Asir $B$G;HMQ2DG=$J7?(B::.

   * $B%G%U%)%k%H$NJQ?t=g=x$O<!$N$h$&$K$J$C$F$$$k(B.

     `x', `y', `z', `u', `v', `w', `p', `q', `r', `s', `t', `a', `b',
     `c', `d', `e', `f', `g', `h', `i', `j', `k', `l', `m', `n',
     `o',$B0J8e$OJQ?t$N8=$l$?=g(B.

     [0] var(x^2+y^2+a^2);
     x
     [1] var(a*b*c*d*e);
     a
     [2] var(3/abc+2*xy/efg);
     abc

$B;2>H(B
     *Note `ord': ord, *Note `vars': vars.

