15304: doctest

Author: rwst

src/sage/symbolic/expression.pyx

@@ -2033,6 +2033,12 @@ cdef class Expression(CommutativeRingElement):
             sage: el = -1/2*(2*x^2 - sqrt(2*x - 1)*sqrt(2*x + 1) - 1)
             sage: el.is_polynomial(x)
             False
+
+        Check that negative exponents are handled (:trac:`15304`)::
+
+            sage: y = var('y')
+            sage: (y/x).is_polynomial(x)
+            False
         """
         cdef Expression symbol0 = self.coerce_in(var)
         return self._gobj.is_polynomial(symbol0._gobj)