This results in an output file where the theorems etc have the section
numbers in their numbering. Eg: Theorem 1.2.1 . I would like to have
the theorems etc numbered sequentially,eg:- Theorem 5. I tried
replacing "Input amsmaths.inc" with "Input amsmaths-seq.inc", but that
resulted in similar errors as before.
Change the Input amsmaths.inc line to Input amsmaths-seq.inc.
As I said, I tried doing this, but it gave similar error messages as
before, about \theoremstyle not being defined.