eja: simplify the way we do field extensions.

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 5679254c37f173809d55922bcaf0b8fbc0f40ac2..515e25f9c97de0ae102e8dc6bd7b29db89e39dd0 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -17,7 +17,7 @@ from sage.misc.prandom import choice
 from sage.misc.table import table
 from sage.modules.free_module import FreeModule, VectorSpace
 from sage.rings.integer_ring import ZZ
-from sage.rings.number_field.number_field import NumberField, QuadraticField
+from sage.rings.number_field.number_field import QuadraticField
 from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
 from sage.rings.rational_field import QQ
 from sage.rings.real_lazy import CLF, RLF
@@ -910,7 +910,7 @@ class MatrixEuclideanJordanAlgebra(FiniteDimensionalEuclideanJordanAlgebra):
             z = R.gen()
             p = z**2 - 2
             if p.is_irreducible():
-                field = NumberField(p, 'sqrt2', embedding=RLF(2).sqrt())
+                field = field.extension(p, 'sqrt2', embedding=RLF(2).sqrt())
                 basis = tuple( s.change_ring(field) for s in basis )
             self._basis_normalizers = tuple(
                 ~(self.natural_inner_product(s,s).sqrt()) for s in basis )
@@ -1277,7 +1277,7 @@ class ComplexMatrixEuclideanJordanAlgebra(MatrixEuclideanJordanAlgebra):
         field = M.base_ring()
         R = PolynomialRing(field, 'z')
         z = R.gen()
-        F = NumberField(z**2 + 1,'i', embedding=CLF(-1).sqrt())
+        F = field.extension(z**2 + 1, 'i', embedding=CLF(-1).sqrt())
         i = F.gen()
 
         # Go top-left to bottom-right (reading order), converting every
@@ -1416,7 +1416,7 @@ class ComplexHermitianEJA(ComplexMatrixEuclideanJordanAlgebra, KnownRankEJA):
         """
         R = PolynomialRing(field, 'z')
         z = R.gen()
-        F = NumberField(z**2 + 1, 'I', embedding=CLF(-1).sqrt())
+        F = field.extension(z**2 + 1, 'I')
         I = F.gen()
 
         # This is like the symmetric case, but we need to be careful: