1 | ;;; -*- Mode: Lisp; Package: Maxima; Syntax: Common-Lisp; Base: 10 -*-
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2 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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3 | ;;;
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4 | ;;; Copyright (C) 1999, 2002, 2009, 2015 Marek Rychlik <rychlik@u.arizona.edu>
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5 | ;;;
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6 | ;;; This program is free software; you can redistribute it and/or modify
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7 | ;;; it under the terms of the GNU General Public License as published by
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8 | ;;; the Free Software Foundation; either version 2 of the License, or
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9 | ;;; (at your option) any later version.
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10 | ;;;
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11 | ;;; This program is distributed in the hope that it will be useful,
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12 | ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 | ;;; GNU General Public License for more details.
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15 | ;;;
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16 | ;;; You should have received a copy of the GNU General Public License
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17 | ;;; along with this program; if not, write to the Free Software
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18 | ;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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19 | ;;;
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20 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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21 |
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22 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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23 | ;;
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24 | ;; Coefficient ring operations
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25 | ;;
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26 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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27 | ;;
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28 | ;; These are ALL operations that are performed on the coefficients by
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29 | ;; the package, and thus the coefficient ring can be changed by merely
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30 | ;; redefining these operations.
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31 | ;;
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32 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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33 |
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34 | (defstruct (ring)
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35 | (parse #'identity :type function)
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36 | (unit #'identity :type function)
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37 | (zerop #'identity :type function)
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38 | (add #'identity :type function)
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39 | (sub #'identity :type function)
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40 | (uminus #'identity :type function)
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41 | (mul #'identity :type function)
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42 | (div #'identity :type function)
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43 | (lcm #'identity :type function)
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44 | (ezgcd #'identity :type function)
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45 | (gcd #'identity :type function))
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46 |
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47 | (defparameter *ring-of-integers*
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48 | (make-ring
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49 | :parse #'identity
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50 | :unit #'(lambda () 1)
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51 | :zerop #'zerop
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52 | :add #'+
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53 | :sub #'-
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54 | :uminus #'-
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55 | :mul #'*
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56 | :div #'/
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57 | :lcm #'lcm
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58 | :ezgcd #'(lambda (x y &aux (c (gcd x y))) (values c (/ x c) (/ y c)))
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59 | :gcd #'gcd)
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60 | "The ring of integers.")
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61 |
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62 | (defvar *expression-ring* *ring-of-integers*
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63 | "The ring of coefficients, over which all polynomials are assumed to
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64 | be defined.")
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