smichr/sympy — comment on commit 7cb7dabf2c6695160b19f372db0bc4cf16069f0b
File: sympy/core/exprtools.py line 527
By jrioux:

I think this note is out-of-sync with the code. It looks to me that all nc parts are replaced by dummies. The example below is also not very useful in elucidating this.