`dp_ord'
--------

dp_ord([ORDER])
     :: Set and show the ordering type.

RETURN
     ordering type (number, list or matrix)

ORDER
     number, list or matrix

   * If an argument is specified, the function sets the current
     ordering type to ORDER.  If no argument is specified, the function
     returns the ordering type currently set.

   * There are two types of functions concerning distributed polynomial,
     functions which take a ordering type and those which don't take it.
     The latter ones use the current setting.

   * Functions such as `gr()', which need a ordering type as an
     argument, call `dp_ord()' internally during the execution.  The
     setting remains after the execution.

     Fundamental arithmetics for distributed polynomial also use the
     current setting. Therefore, when such arithmetics for distributed
     polynomials are done, the current setting must coincide with the
     ordering type which was used upon the creation of the polynomials.
     It is assumed that such polynomials were generated under the same
     ordering type.

   * Type of term ordering must be correctly set by this function when
     functions other than top level functions are called directly.

     [19] dp_ord(0)$
     [20] <<1,2,3>>+<<3,1,1>>;
     (1)*<<1,2,3>>+(1)*<<3,1,1>>
     [21] dp_ord(2)$
     [22] <<1,2,3>>+<<3,1,1>>;
     (1)*<<3,1,1>>+(1)*<<1,2,3>>

References
     *Note `Setting term orderings': Setting term orderings

