Function to transform theano graph <-> sympy graph.
The SymPy -> Theano conversion is implemented and merged into SymPy proper under sympy.printing.theanocode
See the following pull request and blogposts for details on use
sympy/sympy#1905 http://matthewrocklin.com/blog/work/2013/03/19/SymPy-Theano-part-1/ http://matthewrocklin.com/blog/work/2013/03/28/SymPy-Theano-part-2/
There is nothing integrated in Theano to use SymPy simplification automatically.