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15 (* This file was automatically generated: do not edit *********************)
17 set "baseuri" "cic:/matita/CoRN-Decl/algebra/CPoly_Degree".
21 (* $Id: CPoly_Degree.v,v 1.5 2004/04/23 10:00:53 lcf Exp $ *)
23 include "algebra/CPoly_NthCoeff.ma".
25 include "algebra/CFields.ma".
27 (*#* *Degrees of Polynomials
28 ** Degrees of polynomials over a ring
30 Let [R] be a ring and write [RX] for the ring of polynomials
39 inline "cic:/CoRN/algebra/CPoly_Degree/R.var".
46 The length of a polynomial is the number of its coefficients. This is
47 a syntactical property, as the highest coefficient may be [0]. Note that
48 the `zero' polynomial [cpoly_zero] has length [0],
49 a constant polynomial has length [1] and so forth. So the length
50 is always [1] higher than the `degree' (assuming that the highest
51 coefficient is [[#]Zero])!
54 inline "cic:/CoRN/algebra/CPoly_Degree/lth_of_poly.con".
57 When dealing with constructive polynomials, notably over the reals or
58 complex numbers, the degree may be unknown, as we can not decide
59 whether the highest coefficient is [[#]Zero]. Hence,
60 degree is a relation between polynomials and natural numbers; if the
61 degree is unknown for polynomial [p], degree(n,p) doesn't hold for
62 any [n]. If we don't know the degree of [p], we may still
63 know it to be below or above a certain number. E.g. for the polynomial
64 $p_0 +p_1 X +\cdots + p_{n-1} X^{n-1}$#p0 +p1 X + ... + p(n-1)
65 X^(n-1)#, if $p_i \mathrel{\#}0$#pi apart from 0#, we can say that the
66 `degree is at least [i]' and if $p_{j+1} = \ldots =p_n =0$#p(j+1)
67 = ... =pn =0# (with [n] the length of the polynomial), we can say
68 that the `degree is at most [j]'.
71 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le.con".
73 inline "cic:/CoRN/algebra/CPoly_Degree/degree.con".
75 inline "cic:/CoRN/algebra/CPoly_Degree/monic.con".
77 inline "cic:/CoRN/algebra/CPoly_Degree/odd_cpoly.con".
79 inline "cic:/CoRN/algebra/CPoly_Degree/even_cpoly.con".
81 inline "cic:/CoRN/algebra/CPoly_Degree/regular.con".
88 Implicit Arguments degree_le [R].
92 Implicit Arguments degree [R].
96 Implicit Arguments monic [R].
100 Implicit Arguments lth_of_poly [R].
104 Section Degree_props.
107 inline "cic:/CoRN/algebra/CPoly_Degree/R.var".
113 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_wd.con".
115 inline "cic:/CoRN/algebra/CPoly_Degree/degree_wd.con".
117 inline "cic:/CoRN/algebra/CPoly_Degree/monic_wd.con".
119 inline "cic:/CoRN/algebra/CPoly_Degree/degree_imp_degree_le.con".
121 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_c_.con".
123 inline "cic:/CoRN/algebra/CPoly_Degree/degree_c_.con".
125 inline "cic:/CoRN/algebra/CPoly_Degree/monic_c_one.con".
127 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_x_.con".
129 inline "cic:/CoRN/algebra/CPoly_Degree/degree_x_.con".
131 inline "cic:/CoRN/algebra/CPoly_Degree/monic_x_.con".
133 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_mon.con".
135 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_inv.con".
137 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_plus.con".
139 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_minus.con".
141 inline "cic:/CoRN/algebra/CPoly_Degree/Sum_degree_le.con".
143 inline "cic:/CoRN/algebra/CPoly_Degree/degree_inv.con".
145 inline "cic:/CoRN/algebra/CPoly_Degree/degree_plus_rht.con".
147 inline "cic:/CoRN/algebra/CPoly_Degree/degree_minus_lft.con".
149 inline "cic:/CoRN/algebra/CPoly_Degree/monic_plus.con".
151 inline "cic:/CoRN/algebra/CPoly_Degree/monic_minus.con".
153 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_mult.con".
155 inline "cic:/CoRN/algebra/CPoly_Degree/degree_mult_aux.con".
158 Hint Resolve degree_mult_aux: algebra.
161 inline "cic:/CoRN/algebra/CPoly_Degree/monic_mult.con".
163 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_nexp.con".
165 inline "cic:/CoRN/algebra/CPoly_Degree/monic_nexp.con".
167 inline "cic:/CoRN/algebra/CPoly_Degree/lt_i_lth_of_poly.con".
169 inline "cic:/CoRN/algebra/CPoly_Degree/poly_degree_lth.con".
171 inline "cic:/CoRN/algebra/CPoly_Degree/Cpoly_ex_degree.con".
173 inline "cic:/CoRN/algebra/CPoly_Degree/poly_as_sum''.con".
176 Hint Resolve poly_as_sum'': algebra.
179 inline "cic:/CoRN/algebra/CPoly_Degree/poly_as_sum'.con".
181 inline "cic:/CoRN/algebra/CPoly_Degree/poly_as_sum.con".
183 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_zero.con".
185 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_1_imp.con".
187 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_cpoly_linear.con".
189 inline "cic:/CoRN/algebra/CPoly_Degree/monic_cpoly_linear.con".
191 inline "cic:/CoRN/algebra/CPoly_Degree/monic_one.con".
193 inline "cic:/CoRN/algebra/CPoly_Degree/monic_apzero.con".
200 Hint Resolve poly_as_sum'' poly_as_sum' poly_as_sum: algebra.
204 Hint Resolve degree_mult_aux: algebra.
208 Section degree_props_Field.
211 (*#* ** Degrees of polynomials over a field
212 %\begin{convention}% Let [F] be a field and write [FX] for the ring of
213 polynomials over [F].
217 inline "cic:/CoRN/algebra/CPoly_Degree/F.var".
223 inline "cic:/CoRN/algebra/CPoly_Degree/degree_mult.con".
225 inline "cic:/CoRN/algebra/CPoly_Degree/degree_nexp.con".
227 inline "cic:/CoRN/algebra/CPoly_Degree/degree_le_mult_imp.con".
229 inline "cic:/CoRN/algebra/CPoly_Degree/degree_mult_imp.con".
232 End degree_props_Field.