Theorem reference not printing theorem number

Question

My when i am referring a theorem box it is including only the chapter number and section number but not theorem number. Here is the code of theorem tcolorbox

\tcbuselibrary{theorems,skins,hooks}
\newtcbtheorem[number within=section]{Theorem}{Theorem}
{%
    enhanced
    ,breakable
    ,colback = mytheorembg
    ,frame hidden
    ,boxrule = 0sp
    ,borderline west = {2pt}{0pt}{mytheoremfr}
    ,sharp corners
    ,detach title
    ,before upper = \tcbtitle\par\smallskip
    ,coltitle = mytheoremfr
    ,fonttitle = \bfseries\sffamily
    ,description font = \mdseries
    ,separator sign none
    ,segmentation style={solid, mytheoremfr}
}
{th}

Now when i am creating a theorem with a label

\begin{Theorem}{}{} 
    \label{limitpoint} $x$ is a limit point of $S$ $\iff$ every neighborhood of $x$ in $X$ contains a point of $S$ other than $S$.
\end{Theorem}
\ref{limitpoint}

It is only printing 1.1 where as it should print 1.1.1.

Answer 1

The label limitpoints has to be placed in the last mandatory argument and you need to reference it as th:limitpoint because th is what you declared when defining the theorem environment.

\documentclass{book}

\usepackage[many]{tcolorbox}
\tcbuselibrary{theorems,skins,hooks}
\newtcbtheorem[number within=section]{Theorem}{Theorem}{
  enhanced,
  breakable,
  colback = mytheorembg,
  frame hidden,
  boxrule = 0sp,
  borderline west = {2pt}{0pt}{mytheoremfr},
  sharp corners,
  detach title,
  before upper = \tcbtitle\par\smallskip,
  coltitle = mytheoremfr,
  fonttitle = \bfseries\sffamily,
  description font = \mdseries,
  separator sign none,
  segmentation style={solid, mytheoremfr},
}
{th}

\colorlet{mytheorembg}{blue!20}
\colorlet{mytheoremfr}{red!20!blue}

\begin{document}

\chapter{Title}
\section{Title}

\begin{Theorem}{}{limitpoint}
$x$ is a limit point of $S$ if and only if every neighborhood of $x$ in $X$ 
contains a point of $S$ other than $x$.
\end{Theorem}

\ref{th:limitpoint}

\end{document}

I changed the position of all commas because I can't stand seeing them at the left, as they refer to the preceding line.

I also changed $\iff$ into “if and only if”: it costs little to use words instead of mysterious symbols (and fixed the statement).