Consider the following declarations:
\usepackage{amsmath, amsthm, amssymb, thmtools}
\declaretheorem[numberwithin = section]{theorem}
\declaretheorem[sibling = theorem, style = definition]{definition}
\declaretheorem[sibling = theorem]{lemma}
\declaretheorem[sibling = theorem]{proposition}
\declaretheorem[sibling = theorem]{remark}
I want to create a claim theorem which will be used for defining a claim inside the proof of a Theorem. For example,
\begin{proposition}
\begin{proof}
\begin{claim}
first claim
\begin{proof}
proof of first claim
\end{proof}
\end{claim}
\begin{claim}
second claim
\begin{proof}
proof of second claim
\end{proof}
\end{claim}
\end{proof}
\end{proposition}
The first claim should be automatically labeled as "Claim 1", the second claim as "Claim 2", and so on. The text in the proof should be indented such that it's clear where the proof of the individual claim ends without the presence of a q.e.d. symbol.
How can we achieve this? I'm new to latex, so please bear with me.
EDIT: The result should like this:
\begin{theorem}
Text
\begin{proof}[Proof\textup:\nopunct]
Some part of the proof of the main theorem ...\newline
\;\;\;\;\textbf{Claim 1:} Text\newline
\;\;\;\;\textit{Proof}: Line 1\newline
\;\;\;\;Line 2\newline
\;\;\;\;Last Line\newline
\;\;\;\;\;\;\;\;\textbf{Claim 1.1:} Text\newline
\;\;\;\;\;\;\;\;\textit{Proof}: Line 1\newline
\;\;\;\;\;\;\;\;Line 2\newline
\;\;\;\;\;\;\;\;Last Line\newline
continuation of main theorem proof ...
\end{proof}
\end{theorem}
The claim numbering should restart by 1 inside every new theorem proof. Moreover, the claim and its proof should be indented (like $\;\;\;\;$ would do inside an equation). If there is a further claim inside a claim, it should be numbered Claim 1.1 and again be indented (but this time with respect to the environmental claim). How can we do this?