src/sage/rings/polynomial/polynomial_ring.py: Use '# needs sage.libs.ntl' when GF2X is used

Author: Matthias Koeppe

src/sage/rings/polynomial/pbori/pbori.pyx

@@ -3719,7 +3719,7 @@ cdef class BooleanPolynomial(MPolynomial):
             sage: g = R(1)
             sage: h = g.univariate_polynomial(); h
             1
-            sage: h.parent()
+            sage: h.parent()                                                            # needs sage.libs.ntl
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
         """
         if not self.is_univariate():

src/sage/rings/polynomial/polynomial_element.pyx

@@ -10007,12 +10007,12 @@ cdef class Polynomial(CommutativePolynomial):
             Univariate Polynomial Ring in x over Integer Ring
             sage: g = f.map_coefficients(residue, new_base_ring=k); g
             x + 1
-            sage: g.parent()                                                            # optional - sage.rings.finite_rings
+            sage: g.parent()                                                            # needs sage.libs.ntl
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
             sage: residue = k.coerce_map_from(ZZ)
             sage: g = f.map_coefficients(residue); g
             x + 1
-            sage: g.parent()                                                            # optional - sage.rings.finite_rings
+            sage: g.parent()                                                            # needs sage.libs.ntl
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
         """
         R = self._parent

src/sage/rings/polynomial/polynomial_quotient_ring.py

@@ -109,7 +109,7 @@ class PolynomialQuotientRingFactory(UniqueFactory):
 
     ::
 
-        sage: A.<y> = PolynomialRing(GF(2)); A                                          # optional - sage.rings.finite_rings
+        sage: A.<y> = PolynomialRing(GF(2)); A                                          # optional - sage.rings.finite_rings sage.libs.ntl
         Univariate Polynomial Ring in y over Finite Field of size 2 (using GF2X)
         sage: B = A.quotient(y^2 + y + 1, 'y2'); B                                      # optional - sage.rings.finite_rings
         Univariate Quotient Polynomial Ring in y2 over Finite Field of size 2

src/sage/rings/polynomial/polynomial_ring.py

@@ -1266,13 +1266,13 @@ def is_exact(self):
 
     def is_field(self, proof=True):
         """
-        Return False, since polynomial rings are never fields.
+        Return ``False``, since polynomial rings are never fields.
 
         EXAMPLES::
 
-            sage: R.<z> = Integers(2)[]; R
+            sage: R.<z> = Integers(2)[]; R                                              # needs sage.libs.ntl
             Univariate Polynomial Ring in z over Ring of integers modulo 2 (using GF2X)
-            sage: R.is_field()
+            sage: R.is_field()                                                          # needs sage.libs.ntl
             False
         """
         return False
@@ -3251,7 +3251,7 @@ def residue_field(self, ideal, names=None):
 
         EXAMPLES::
 
-            sage: # needs sage.rings.finite_rings
+            sage: # needs sage.libs.ntl
             sage: R.<t> = GF(2)[]
             sage: k.<a> = R.residue_field(t^3 + t + 1); k
             Residue field in a
@@ -3301,9 +3301,9 @@ def __init__(self, base_ring, name="x", implementation=None, element_class=None,
         """
         TESTS::
 
-            sage: P = GF(2)['x']; P                                                     # needs sage.rings.finite_rings
+            sage: P = GF(2)['x']; P                                                     # needs sage.libs.ntl
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
-            sage: type(P.gen())                                                         # needs sage.rings.finite_rings
+            sage: type(P.gen())                                                         # needs sage.libs.ntl
             <class 'sage.rings.polynomial.polynomial_gf2x.Polynomial_GF2X'>
 
             sage: from sage.rings.polynomial.polynomial_ring import PolynomialRing_dense_mod_p
@@ -3371,19 +3371,20 @@ def _implementation_names_impl(implementation, base_ring, sparse):
         """
         TESTS::
 
-            sage: # needs sage.rings.finite_rings
+            sage: # needs sage.libs.ntl
             sage: PolynomialRing(GF(2), 'x', implementation="GF2X")
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
             sage: PolynomialRing(GF(2), 'x', implementation="NTL")
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
             sage: PolynomialRing(GF(2), 'x', implementation=None)
             Univariate Polynomial Ring in x over Finite Field of size 2 (using GF2X)
-            sage: PolynomialRing(GF(2), 'x', implementation="FLINT")
-            Univariate Polynomial Ring in x over Finite Field of size 2
             sage: PolynomialRing(GF(3), 'x', implementation="GF2X")
             Traceback (most recent call last):
             ...
             ValueError: GF2X only supports modulus 2
+
+            sage: PolynomialRing(GF(2), 'x', implementation="FLINT")                    # needs sage.libs.flint
+            Univariate Polynomial Ring in x over Finite Field of size 2
         """
         if sparse:
             return NotImplemented