---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-11-d4f77a7d88d7> in <module>()
----> 1 d.cdf(Integer(10) - sqrt(Integer(20)))

/home/mmeh/sage/local/lib/python2.7/site-packages/scipy/stats/distributions.pyc in cdf(self, x)
    434
    435     def cdf(self, x):
--> 436         return self.dist.cdf(x, *self.args, **self.kwds)
    437
    438     def logcdf(self, x):

/home/mmeh/sage/local/lib/python2.7/site-packages/scipy/stats/distributions.pyc in cdf(self, x, *args, **kwds)
   1292         x = (x-loc)*1.0/scale
   1293         cond0 = self._argcheck(*args) & (scale > 0)
-> 1294         cond1 = (scale > 0) & (x > self.a) & (x < self.b)
   1295         cond2 = (x >= self.b) & cond0
   1296         cond = cond0 & cond1

TypeError: unsupported operand type(s) for &: 'bool' and 'sage.symbolic.expression.Expression'