'Sum' has no attribute from summing two `Expression`s

[Damon McDougall]

In [1]: import dolfin as df

In [3]: t = 0

In [5]: a = df.Expression('x[0] + t', t=t)

In [6]: b = df.Expression('x[1] + t', t=t)
Calling DOLFIN just-in-time (JIT) compiler, this may take some time.

In [7]: c = a + b

In [9]: c.t
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-9-2e2523e7e18d> in <module>()
----> 1 c.t

AttributeError: 'Sum' object has no attribute 't'

[Martin Sandve Alnæs]

This is not expected to work, this is not a bug.

[Damon McDougall]

Thanks for clarifying.