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:- protocol(datep).
:- info([
version is 1.1,
author is 'Paulo Moura',
date is 2005/3/17,
comment is 'Date protocol.']).
:- public(today/3).
:- mode(today(-integer, -integer, -integer), one).
:- info(today/3, [
comment is 'Returns current date.',
argnames is ['Year', 'Month', 'Day']]).
:- public(leap_year/1).
:- mode(leap_year(+integer), zero_or_one).
:- info(leap_year/1,
[comment is 'True if the argument is a leap year.',
argnames is ['Year']]).
:- public(name_of_day/3).
:- mode(name_of_day(?integer, ?atom, ?atom), zero_or_more).
:- info(name_of_day/3, [
comment is 'Name and short name of day.',
argnames is ['Index', 'Name', 'Short']]).
:- public(name_of_month/3).
:- mode(name_of_month(?integer, ?atom, ?atom), zero_or_more).
:- info(name_of_month/3, [
comment is 'Name and short name of month.',
argnames is ['Index', 'Name', 'Short']]).
:- public(days_in_month/3).
:- mode(days_in_month(?integer, +integer, ?integer), zero_or_more).
:- info(days_in_month/3, [
comment is 'Number of days in a month.',
argnames is ['Month', 'Year', 'Days']]).
:- public(valid/3).
:- mode(valid(@integer, @integer, @integer), zero_or_one).
:- info(valid/3, [
comment is 'True if the arguments represent a valid date.',
argnames is ['Year', 'Month', 'Day']]).
:- end_protocol.
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