Remove assumptions on the Normed class.

[numerical-analysis.git] / src / Roots / Fast.hs

diff --git a/src/Roots/Fast.hs b/src/Roots/Fast.hs
index 78c299ad6a2cc39629b409bff5eed86787a3ca20..0deb1fd6237a5909ea7d15a252f09b524093d1bf 100644 (file)
--- a/src/Roots/Fast.hs
+++ b/src/Roots/Fast.hs
@@ -14,6 +14,8 @@ import Normed
 
 import NumericPrelude hiding (abs)
 import qualified Algebra.Absolute as Absolute
+import qualified Algebra.Additive as Additive
+import qualified Algebra.Algebraic as Algebraic
 import qualified Algebra.Field as Field
 import qualified Algebra.RealRing as RealRing
 import qualified Algebra.RealField as RealField
@@ -116,9 +118,9 @@ fixed_point_iterations f x0 =
 --   We also return the number of iterations required.
 --
 fixed_point_with_iterations :: (Normed a,
-                                Field.C b,
-                                Absolute.C b,
-                                Ord b)
+                                Algebraic.C a,
+                                RealField.C b,
+                                Algebraic.C b)
                             => (a -> a)  -- ^ The function @f@ to iterate.
                             -> b        -- ^ The tolerance, @epsilon@.
                             -> a        -- ^ The initial value @x0@.