Fix bug in SeriesStream.is_constant()

sagemath · Jan 13, 2014 · d2d753e · d2d753e
1 parent bdad7a3
commit d2d753e
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/sage/combinat/species/series_stream.py b/src/sage/combinat/species/series_stream.py
@@ -370,16 +370,16 @@ def compute(self, n):
         return res
 
     def is_constant(self):
-        return ((self._left.is_constant() and self._left.is_constant() == 0) and
-                (self._right.is_constant() and self._right.is_constant() == 0))
+        return ((self._left.is_constant() and self._left.get_constant() == 0) and
+                (self._right.is_constant() and self._right.get_constant() == 0))
 
     def get_constant(self):
         assert self.is_constant()
         return self._base_ring(0)
 
     def get_constant_position(self):
         return (self._left.get_constant_position() *
-                self._right.get_constant_position()) - 1
+                self._right.get_constant_position())
 
 
 class TailStream(SeriesStream):