`vtype'
-------

vtype(VAR)
     :: Type of indetarminates VAR.

RETURN
     integer

VAR
     indeterminate

   * Classify indeterminates into sub-types by giving an integer value
     as follows.  For details  *Note Types of indeterminates::.
    0
          ordinary indeterminate, which can be directly typed in on a
          keyboard (a,b,x,afo,bfo,...,etc.)

    1
          Special indeterminate, created by `uc()' (`_0', `_1', `_2',
          ... etc.)

    2
          function form (`sin(x)', `log(a+1)', `acosh(1)', `@pi', `@e',
          ... etc.)

    3
          functor (built-in functor name, user defined functor, functor
          for the elementary functions)  : `sin', `log', ... etc)

   * Note: An input ``a();'' will cause an error, but it changes the
     system database for identifiers.  After this error, you will find
     ``vtype(a)'' will result 3. (Identifier `a' is registered as a
     user defined functor).

   * Usually `@pi' and `@e' are treated as indeterminates, whereas they
     are treated as numbers within functions `eval()' and  `pari()'.

References
     *Note `type': type, *Note `ntype': ntype, *Note `uc': uc.

