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Diffstat (limited to 'vikalpa/primitive.scm')
| -rw-r--r-- | vikalpa/primitive.scm | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/vikalpa/primitive.scm b/vikalpa/primitive.scm new file mode 100644 index 0000000..bcbced5 --- /dev/null +++ b/vikalpa/primitive.scm @@ -0,0 +1,25 @@ +;;; Vikalpa --- Proof Assistant +;;; Copyright © 2020 Masaya Tojo <masaya@tojo.tokyo> +;;; +;;; This file is part of Vikalpa. +;;; +;;; Vikalpa is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; Vikalpa is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;;; General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with Vikalpa. If not, see <http://www.gnu.org/licenses/>. + +(define-module (vikalpa primitive) + #:export (natural?)) + +;; (natural? x) -> boolean? +(define (natural? x) + (and (integer? x) + (not (negative? x)))) |