sympy/sympy — pull request #8592 by rwst (2014-12-09 09:44:25+00:00)
Title: provide Function._sage_; remove superfluous _sage_ methods; add more of them

this should enable all bindings between symbolic functions in SymPy and Sage which are possible at the moment and, for identical names, in the future

depends on #8585

also fixes http://trac.sagemath.org/ticket/14723