PLOGHELP NUMBERVARS                                 Chris Mellish 8/7/83
                                Revised by Kathryn Seifert  October 1986

Predicate which can be used to set how variables are written

    ?- numbervars(Term, Number1, Number2).

Keywords: output, write, display, variables

Causes all the variables in Term to be instantiated to terms of the form
'$VAR'(N), where N is an integer.  Non-sharing variables are allocated
different integers.  The numbers go from Number1 to Number2 - 1. Number1
must initially be instantiated, but Number2 need not.

The predicates 'write' and 'display' recognise terms of the form
'$VAR'(N) specially and write them out as an underline character ("_")
followed by the number (ie in the same basic format as uninstantiated
variables are normally written in).

For example:

    ?- numbervars(pig(Fat, Hungry, Smelly), 950, X).
    Fat = _950
    Hungry = _951
    Smelly = _952
    X = 953 ? 
    yes

-- RELATED DOCUMENTATION ----------------------------------------------

PLOGHELP * WRITE
 Predicate which writes a term to current output (not in prefix format)

PLOGHELP * DISPLAY
 Predicate which writes argument to current output in prefix format

PLOGHELP * I_O
 Overview of input/output operations in Prolog