@kcrisman thanks for paying attention. I added now an updated patch and extended instructions.

the doctest changes in **symbolic.random_tests.py** are easy to explain: new functions are involved -> new random expressions. But I had to change
`random_expr(50, nvars=3, coeff_generator=CDF.random_element) `

to `random_expr(60, nvars=3, coeff_generator=CDF.random_element) `

or else one gets an expression generated where a division through zero occours.

As mentioned on sage-devel I repaired the doctests in **symbolic.pynac.pyx**, the trick is to enlarge the range of the for loop:
`for i in range(get_ginac_serial(), get_ginac_serial()+50):`

changed to
`for i in range(get_ginac_serial(), get_ginac_serial()+100):`

now it works. My explaination: since we have new functions we have longer to search, and then we reach our goal. What I can not explain is, that it works, when I type it in by hand.

All doctests pass now, so I think a review would be nice.

-maldun