tesserahub/sympy — comment on commit 914150225ace08c79f00b17838e34b94276856ce
File: sympy/stats/crv_types.py line 175
By mrocklin:

The Piecewise can be dropped. It is handled by the set = Interval(0, oo) keyword below. Piecewises tend to foul up the integrator. See Exponential for a case where this works smoothly