@@ -180,55 +180,58 @@ cdef class FunctionFieldElement(FieldElement):
180
180
A rational function field::
181
181
182
182
sage: K. <t> = FunctionField( QQ)
183
- sage: t. matrix( ) # needs sage. modules
183
+ sage: t. matrix( ) # needs sage. modules
184
184
[t ]
185
- sage: ( 1/( t+ 1)) . matrix( ) # needs sage. modules
185
+ sage: ( 1/( t+ 1)) . matrix( ) # needs sage. modules
186
186
[1/(t + 1) ]
187
187
188
188
Now an example in a nontrivial extension of a rational function field::
189
189
190
+ sage: # needs sage. modules sage. rings. function_field
190
191
sage: K. <x> = FunctionField( QQ) ; R. <y> = K[]
191
- sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3) # needs sage . rings . function_field
192
- sage: y. matrix( ) # needs sage . modules sage . rings . function_field
192
+ sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3)
193
+ sage: y. matrix( )
193
194
[ 0 1 ]
194
195
[-4*x^3 x ]
195
- sage: y. matrix( ) . charpoly( 'Z') # needs sage . modules sage . rings . function_field
196
+ sage: y. matrix( ) . charpoly( 'Z')
196
197
Z^ 2 - x* Z + 4* x^ 3
197
198
198
199
An example in a relative extension, where neither function
199
200
field is rational::
200
201
202
+ sage: # needs sage. modules sage. rings. function_field
201
203
sage: K. <x> = FunctionField( QQ)
202
204
sage: R. <y> = K[]
203
- sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3) # needs sage . rings . function_field
204
- sage: M. <T> = L[] # needs sage . rings . function_field
205
- sage: Z. <alpha> = L. extension( T^ 3 - y^ 2* T + x) # needs sage . rings . function_field
206
- sage: alpha. matrix( ) # needs sage . modules sage . rings . function_field
205
+ sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3)
206
+ sage: M. <T> = L[]
207
+ sage: Z. <alpha> = L. extension( T^ 3 - y^ 2* T + x)
208
+ sage: alpha. matrix( )
207
209
[ 0 1 0 ]
208
210
[ 0 0 1 ]
209
211
[ -x x*y - 4*x^3 0 ]
210
- sage: alpha. matrix( K) # needs sage . modules sage . rings . function_field
212
+ sage: alpha. matrix( K)
211
213
[ 0 0 1 0 0 0 ]
212
214
[ 0 0 0 1 0 0 ]
213
215
[ 0 0 0 0 1 0 ]
214
216
[ 0 0 0 0 0 1 ]
215
217
[ -x 0 -4*x^3 x 0 0 ]
216
218
[ 0 -x -4*x^4 -4*x^3 + x^2 0 0 ]
217
- sage: alpha. matrix( Z) # needs sage . modules sage . rings . function_field
219
+ sage: alpha. matrix( Z)
218
220
[alpha ]
219
221
220
222
We show that this matrix does indeed work as expected when making a
221
223
vector space from a function field::
222
224
225
+ sage: # needs sage. modules sage. rings. function_field
223
226
sage: K. <x> = FunctionField( QQ)
224
227
sage: R. <y> = K[]
225
- sage: L. <y> = K. extension( y^ 5 - ( x^ 3 + 2* x* y + 1/x)) # needs sage . rings . function_field
226
- sage: V, from_V, to_V = L. vector_space( ) # needs sage . modules sage . rings . function_field
227
- sage: y5 = to_V( y^ 5) ; y5 # needs sage . modules sage . rings . function_field
228
+ sage: L. <y> = K. extension( y^ 5 - ( x^ 3 + 2* x* y + 1/x))
229
+ sage: V, from_V, to_V = L. vector_space( )
230
+ sage: y5 = to_V( y^ 5) ; y5
228
231
(( x^ 4 + 1) /x, 2* x, 0, 0, 0)
229
- sage: y4y = to_V( y^ 4) * y. matrix( ) ; y4y # needs sage . modules sage . rings . function_field
232
+ sage: y4y = to_V( y^ 4) * y. matrix( ) ; y4y
230
233
(( x^ 4 + 1) /x, 2* x, 0, 0, 0)
231
- sage: y5 == y4y # needs sage . modules sage . rings . function_field
234
+ sage: y5 == y4y
232
235
True
233
236
"""
234
237
# multiply each element of the vector space isomorphic to the parent
@@ -363,17 +366,18 @@ cdef class FunctionFieldElement(FieldElement):
363
366
364
367
EXAMPLES::
365
368
369
+ sage: # needs sage. modules sage. rings. function_field
366
370
sage: K. <x> = FunctionField( QQ) ; R. <y> = K[]
367
- sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3) # needs sage . rings . function_field
368
- sage: y. is_integral( ) # needs sage . rings . function_field
371
+ sage: L. <y> = K. extension( y^ 2 - x* y + 4* x^ 3)
372
+ sage: y. is_integral( )
369
373
True
370
- sage: ( y/x) . is_integral( ) # needs sage . modules sage . rings . function_field
374
+ sage: ( y/x) . is_integral( )
371
375
True
372
- sage: ( y/x) ^ 2 - ( y/x) + 4* x # needs sage . modules sage . rings . function_field
376
+ sage: ( y/x) ^ 2 - ( y/x) + 4* x
373
377
0
374
- sage: ( y/x^ 2) . is_integral( ) # needs sage . modules sage . rings . function_field
378
+ sage: ( y/x^ 2) . is_integral( )
375
379
False
376
- sage: ( y/x) . minimal_polynomial( 'W') # needs sage . modules sage . rings . function_field
380
+ sage: ( y/x) . minimal_polynomial( 'W')
377
381
W^ 2 - W + 4* x
378
382
"""
379
383
R = self .parent().base_field().maximal_order()
@@ -609,11 +613,12 @@ cdef class FunctionFieldElement(FieldElement):
609
613
610
614
::
611
615
616
+ sage: # needs sage.rings.function_field
612
617
sage: K.<x> = FunctionField(QQ); _.<Y> = K[]
613
- sage: L.<y> = K.extension(Y^2 + Y + x + 1/x) # needs sage.rings.function_field
614
- sage: O = L.maximal_order() # needs sage.rings.function_field
615
- sage: p = O.ideal(x - 1).place() # needs sage.rings.function_field
616
- sage: y.valuation(p) # needs sage.rings.function_field
618
+ sage: L.<y> = K.extension(Y^2 + Y + x + 1/x)
619
+ sage: O = L.maximal_order()
620
+ sage: p = O.ideal(x - 1).place()
621
+ sage: y.valuation(p)
617
622
0
618
623
"""
619
624
prime = place.prime_ideal()
0 commit comments