Symplify TypeError messages in Expression.__new__

diff --git a/pypol/linexprs.py b/pypol/linexprs.py
index 5ec5efd..b23eea8 100644 (file)
--- a/pypol/linexprs.py
+++ b/pypol/linexprs.py
@@ -65,14 +65,12 @@ class Expression:
             if isinstance(coefficient, Rational):
                 coefficient = coefficient.constant
             if not isinstance(coefficient, numbers.Rational):
-                raise TypeError('coefficients must be rational numbers '
-                    'or Rational instances')
+                raise TypeError('coefficients must be Rational instances')
             self._coefficients[symbol] = coefficient
         if isinstance(constant, Rational):
             constant = constant.constant
         if not isinstance(constant, numbers.Rational):
-            raise TypeError('constant must be a rational number '
-                'or a Rational instance')
+            raise TypeError('constant must be a Rational instance')
         self._constant = constant
         self._symbols = tuple(self._coefficients)
         self._dimension = len(self._symbols)