I'm a bit confused about where to put commata in a "though, since, for example" construction. The sentence I used reads:
The class of cofibrant objects is larger than the class of CW--complexes, though, since, for example, a retract of a cellular map is not necessarily cellular.
This looks horrible and hard to read, imho. Googling for "though since for example" yielded various variations of comma placements, including mine. So the question is: which of the four commata may I omit, if any.
Edit To avoid problems with the technical details, the sentence syntactically identical to
Not everything that grows on a tree is a fruit, though, since, for example, walnuts grow on trees.