Remove an unused import

[linpy.git] / linpy / domains.py

diff --git a/linpy/domains.py b/linpy/domains.py
index 4b3e982..581a065 100644 (file)
--- a/linpy/domains.py
+++ b/linpy/domains.py
@@ -24,7 +24,7 @@ from fractions import Fraction
 
 from . import islhelper
 from .islhelper import mainctx, libisl
-from .linexprs import LinExpr, Symbol, Rational
+from .linexprs import LinExpr, Symbol
 from .geometry import GeometricObject, Point, Vector
 
 
@@ -38,7 +38,7 @@ __all__ = [
 class Domain(GeometricObject):
     """
     A domain is a union of polyhedra. Unlike polyhedra, domains allow exact
-    computation of union and complementary operations.
+    computation of union, subtraction and complementary operations.
 
     A domain with a unique polyhedron is automatically subclassed as a
     Polyhedron instance.
@@ -599,7 +599,7 @@ class Domain(GeometricObject):
         elif self.dimension == 3:
             return self._plot_3d(plot=plot, **kwargs)
         else:
-            raise ValueError('polyhedron must be 2 or 3-dimensional')
+            raise ValueError('domain must be 2 or 3-dimensional')
 
     def subs(self, symbol, expression=None):
         """
@@ -703,17 +703,17 @@ class Domain(GeometricObject):
         Create a domain from a string. Raise SyntaxError if the string is not
         properly formatted.
         """
-        # remove curly brackets
+        # Remove curly brackets.
         string = cls._RE_BRACES.sub(r'', string)
-        # replace '=' by '=='
+        # Replace '=' by '=='.
         string = cls._RE_EQ.sub(r'\1==\2', string)
-        # replace 'and', 'or', 'not'
+        # Replace 'and', 'or', 'not'.
         string = cls._RE_AND.sub(r' & ', string)
         string = cls._RE_OR.sub(r' | ', string)
         string = cls._RE_NOT.sub(r' ~', string)
-        # add implicit multiplication operators, e.g. '5x' -> '5*x'
+        # Add implicit multiplication operators, e.g. '5x' -> '5*x'.
         string = cls._RE_NUM_VAR.sub(r'\1*\2', string)
-        # add parentheses to force precedence
+        # Add parentheses to force precedence.
         tokens = cls._RE_OPERATORS.split(string)
         for i, token in enumerate(tokens):
             if i % 2 == 0:
@@ -737,7 +737,7 @@ class Domain(GeometricObject):
     @classmethod
     def fromsympy(cls, expr):
         """
-        Create a domain from a sympy expression.
+        Create a domain from a SymPy expression.
         """
         import sympy
         from .polyhedra import Lt, Le, Eq, Ne, Ge, Gt
@@ -756,7 +756,7 @@ class Domain(GeometricObject):
 
     def tosympy(self):
         """
-        Convert the domain to a sympy expression.
+        Convert the domain to a SymPy expression.
         """
         import sympy
         polyhedra = [polyhedron.tosympy() for polyhedron in polyhedra]
@@ -772,7 +772,6 @@ def And(*domains):
         return Universe
     else:
         return domains[0].intersection(*domains[1:])
-And.__doc__ = Domain.intersection.__doc__
 
 def Or(*domains):
     """
@@ -783,11 +782,9 @@ def Or(*domains):
         return Empty
     else:
         return domains[0].union(*domains[1:])
-Or.__doc__ = Domain.union.__doc__
 
 def Not(domain):
     """
     Create the complementary domain of the domain given in argument.
     """
     return ~domain
-Not.__doc__ = Domain.complement.__doc__