`var'
-----

var(RAT)
     :: Main variable (indeterminate) of RAT.

RETURN
     indeterminate

RAT
     rational expression

   * See *Note Types in Asir:: for main variable.

   * Indeterminates (variables) are ordered by default as follows.

     `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'.
     The other variables will be ordered after the above noted variables
     so that the first comer will be ordered prior to the followers.

     [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

References
     *Note `ord': ord, *Note `vars': vars.

