:: Numerals - Requirements
:: by Library Committee
::
:: Received February 27, 2003
:: Copyright (c) 2003-2017 Association of Mizar Users
:: (Stowarzyszenie Uzytkownikow Mizara, Bialystok, Poland).
:: This code can be distributed under the GNU General Public Licence
:: version 3.0 or later, or the Creative Commons Attribution-ShareAlike
:: License version 3.0 or later, subject to the binding interpretation
:: detailed in file COPYING.interpretation.
:: See COPYING.GPL and COPYING.CC-BY-SA for the full text of these
:: licenses, or see http://www.gnu.org/licenses/gpl.html and
:: http://creativecommons.org/licenses/by-sa/3.0/.
environ
vocabularies XBOOLE_0, SUBSET_1, ORDINAL1;
notations XBOOLE_0, SUBSET_1, ORDINAL1;
constructors SUBSET_1, ORDINAL1;
requirements BOOLE;
begin
:: This file contains statements which are obvious for Mizar checker if
:: "requirements NUMERALS" is included in the environment description
:: of an article. They are published for testing purposes only.
:: Users should use appropriate requirements instead of referencing
:: to these theorems.
:: Some of these items need also other requirements for proper work.
:: Statements which cannot be expressed in Mizar language are commented out.
theorem :: NUMERALS:1
{} is Element of omega;
::theorem
:: numeral(X) implies X is Element of omega;
::theorem
:: numeral(X) implies succ(X) = X + 1;