controlling theorem numbers using llncs style

Question

Is there a way to control the numbering of different types of theorems, when using the llncs style?

With the envcountsame parameter, all theorems/definitions/claims use the same counter and get sequential numbering. What I'd like to have is that Theorems / Propositions / Lemmas will use one counter, and Definitions will use a different counter (also Remarks should use a new counter, maybe the one of Lemmas maybe totally fresh one).

Suggestions?

Answer 1

You can define new theorem-like environments numbered as you like. If you want definitions to use their own counter, you can do

\spnewtheorem{defn}{Definition}{\bfseries}{\rmfamily}

and this will do. You could also redefine the definition environment:

\documentclass[envcountsame]{llncs}

\let\definition\relax % undefine the environment
\spnewtheorem{definition}{Definition}{\bfseries}{\rmfamily}

\begin{document}
\begin{lemma}
Lemma
\end{lemma}
\begin{theorem}
Theorem
\end{theorem}
\begin{definition}
Definition
\end{definition}
\end{document}

This might be even better, so you can revert to the usual class setting just by commenting the two lines.