I am trying to write theorems that will number based on section and subsection.

I know this is the default when you enter, for example:


but when I do this, it only shows the subsection, not the section. I think this may be because I have renamed my subsections to be lettered instead of numbered with the command:


My sections are numbered (1, 2, 3, etc.) and my subsections are lettered (A, B, C, etc.) When I use the \newtheorem command I get:

Definition A.1 instead of Definition 1.A.1

Any idea why it is dropping the section number and how to fix? (I am using the amsart document class)

  • It would be really helpful to have a compilable document, not just fragments. Are you really using amsart? – user31729 May 17 '16 at 15:53
  • maybe you should be using \numberwithin{section}{chapter}. – barbara beeton May 17 '16 at 15:56

Is this what is requested?

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The redefinition of \thesubsection as {\Alph{subsection}} strips the section information of course from \thesubsection.

\thedefn is using \thesubsection.\arabic{defn} due to its definition, so \thesection is missing then.







\subsection{Foo subsection}


  • This is exactly the answer I was looking for. Thank you! Much appreciated. – hp_ May 18 '16 at 15:18

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