The following are the current version of the grading functions used for grading the quality of the antiderivative with reference to the optimal antiderivative included in the test suite.
There is a version for Maple and for Mathematica/Rubi. There is a version for grading Sympy and version for use with Sagemath.
The following are links to the current source code.
The following are the listings of source code of the grading functions.