I have been dealing with the Tosphot on the top of the page in Sanhedrin 63a.
I wrote about this in a blog entry a few days ago but now I want to add.
The way Tosphot is looking at this according to the Maharsha is that "Don't serve" is a exclusionary principle. [It comes to exclude something] We had before that all kinds of services were forbidden and then "Don't serve"  puts the three inner services into one and comes to exclude the three from the normal category.
And then what is left for "Don't bow" to tell us? Only what is left in the larger category--that is- itself.
That is how the Maharsha is explaining Tosphot. [This is the view of R Ami. And this is good because it allows bowing to tell us about the whole category. And this shows why R Yochanan did not accept R Zakai's approach since it has bowing to teach about itself alone. And that is no good. It goes against the principle what ever was in a category and is mentioned separately goes out to teach about the whole category.]
The Maharam adds an important observation  that R. Zakai never needed "Don't serve" to make  any kinds of idolatry into one category. There was no reason in the first place to divide them.[Not like in Shabat where we have אחת מהנה to divide.] [That is: that bowing did not leave the category of "Don't serve" because don't serve was not a general category.]
But to the Maharsha everyone agrees with Abyee that  "bowing" comes to divide. Only  the fact that "Don't serve" took the three inner services out of the larger category means that they don't get divided.
In any case, both the Maharsha and Maharam explain Tosphot well and differently than I was doing. Because I thought that R. Zakai was in fact using "Don't serve" to include all four services. This is clearly not what Tosphot was saying, and it was a mistake on my part.

In the long run, however, it looks like the fact is that R. Zakai is considering R. Ami's idea that "bowing" can be refering to the whole category when it is in fact only referring to itself as wrong.
But the way I was putting this idea was sloppy and I apologize for that.

In summary:

What is happening is Tosphot says that R Zakai is not using the "drasha" on  "Don't serve." The way the Maharsha explains that is to say "Don't serve" came out of the general category of service, not the opposite in which bowing comes out. So bowing is in the category and never left it and so does not need to teach anything about the general category. The Maharam deals with it by saying R. Zakai never needed "Don't serve."

[I am not saying everything here is fine. This obviously still needs a lot of work. But right now all I am doing is to try and get how the Maharsha and Maharam understand Tosphot. If we can get that down pat, then we can then go and try to figure out the many obvious questions here. ]