PLOGHELP MINUS                             Kathryn Seifert  October 1986

Operator to subtract one number from another

    ?- X is <num> - <num>.

Keywords: subtraction, arithmetic expressions, arithmetic, evaluation

To subtract one number from another, use the minus sign, with the
operator "is":

        ?- X is 2 - 1.
        X = 1 ?

You can negate numbers too:

        ?- X is 3, Y is -X.
        X = 3
        Y = -3 ?

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

PLOGHELP * ARITHMETIC
 Overview of HELP files dealing with operations on numbers.

PLOGHELP * IS
 Evaluating POP-11 and arithmetic expressions which return one result

PLOGHELP * SYMBOLS
 Summary and index of HELP files for symbols used in Prolog

PLOGHELP * OPERATORS
 Operator declarations made when the Prolog system is loaded

PLOGHELP * OP
 How to declare operators