Is it a good idea to combine the glossary and the list of notations in a mathematical PhD thesis? I am considering including a glossary and a list of notations in my PhD thesis on mathematics. Is it a good idea to write them separately or combine them? 

For example, a typical entry of the list of notation is:

[a,b] The commutator of a and b, defined by [a,b]=a^{-1}b^{-1}ab.

An entry of the glossary is:

Commutator The commutator of a and b is defined to be the product a^{-1}b^{-1}ab.

(Note: the definition of commutator is well-known to mathematicians, but since another definition aba^{-1}b^{-1} is also possible, I would like to add the definition to avoid any possible ambiguity.)

I have a strong feeling of combining these two entries together, maybe even combining the glossary and the list of notations together.

Is it a good idea to combine the glossary and the list of notations in a mathematical PhD thesis?
Have your definitions in line rather than in a glossary, it improves the readability of the entire manuscript (whether or not those definitions are actually necessary). People rarely go through glossaries anyway, since it would involve spending twice the amount of time just to switch pages back and forth. Inline definitions, instead, help the reader to flow on without dismissing the attention on the context.