Remove an unused import

[linpy.git] / linpy / domains.py

diff --git a/linpy/domains.py b/linpy/domains.py
index 799b99d..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 . import islhelper
 from .islhelper import mainctx, libisl

-from .linexprs import LinExpr, Symbol, Rational
+from .linexprs import LinExpr, Symbol

 from .geometry import GeometricObject, Point, Vector
 
 
 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
 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.
 
     A domain with a unique polyhedron is automatically subclassed as a
     Polyhedron instance.


@@ -703,17 +703,17 @@ class Domain(GeometricObject):
         Create a domain from a string. Raise SyntaxError if the string is not
         properly formatted.
         """
         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)
         string = cls._RE_BRACES.sub(r'', string)

-        # replace '=' by '=='
+        # Replace '=' by '=='.

         string = cls._RE_EQ.sub(r'\1==\2', string)
         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)
         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)
         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:
         tokens = cls._RE_OPERATORS.split(string)
         for i, token in enumerate(tokens):
             if i % 2 == 0: