diff --git a/doc/environments/groupthm/groupthm.tex b/doc/environments/groupthm/groupthm.tex
index e1ce07f..474a8db 100644
--- a/doc/environments/groupthm/groupthm.tex
+++ b/doc/environments/groupthm/groupthm.tex
@@ -26,7 +26,6 @@
 \begin{document}
 \maketitle
 
-\section{test}
 \begin{documentation}
 
 \tableofcontents
@@ -96,6 +95,18 @@ of conflicting properties of different \meta{theorem group}s a \meta{theorem} ma
 
 This hierarchy can of course be controlled by the user.
 
+\subsection{Grouped theorems}
+
+A \meta{grouped theorem} is just a theorem that is a member of
+a given set of groups (possibly empty).
+It behaves just a regular theorem, except that by changing the definition of
+its theorem groups, we can alter its behavior.
+
+
+It is the core concept of the \pkg{groupthm} package.
+For brevity, we will often talk about \enquote{theorems},
+although in fact we mean \enquote{grouped theorems}.
+
 \subsection{Theorem families}
 Often, one needs some small \meta{theorem variant}s of some \meta{theorem}, the most typical
 example being \vocab{starred} version of \meta{theorem}s that are not numbered
@@ -138,7 +149,58 @@ of the \meta{theorem family}, which then controls the membership in these groups
 (and of course prior to this the definition of the desired \meta{theorem group}s).
 
 
-\section{End user interface}
+
+\subsection{General notions}
+
+In many cases, there are a number of variants of some command,
+call it for example \cs{Foo}.
+Then the documentation will look like
+%
+\begin{function}{\NewFoo, \RenewFoo, \ProvideFoo, \DeclareFoo}
+  Defines some \kw{foo} \ldots
+\end{function}
+%
+and will not mention anything about the variants.
+This follows some general naming convention that also \pkg{xparse} uses,
+and is the following:
+
+  \begin{description}
+    \item[\cs{NewFoo}]
+
+      Defines \kw{foo} if not defined already.
+      This emits an error in case it has been defined yet.
+
+    \item[\cs{RenewFoo}]
+
+      Redefines \kw{foo} if defined already.
+      This emits an error in case it has \emph{not} been defined yet.
+
+    \item[\cs{ProvideFoo}]
+
+      Defines \kw{foo} if it is not defined already.
+      This does not emit an error if \kw{foo} is already defined
+      (and has no effect in this case).
+
+    \item[\cs{DeclareFoo}]
+
+      Defines \kw{foo} in disregard of any
+      existing definitions. Any old definition will be overwritten (if present).
+  \end{description}
+%
+  The documentation margin will list all variants that are available,
+  they follow their respective conventions.
+
+
+  \begin{texnote}
+    The \pkg{thmtools} package, unfortunately, dose not follow this convention,
+    as its \cs{declaretheorem} command actually behaves like a \cs{newtheorem}.
+    The reason for this is that \pkg{amsthm} already defines \cs{newtheorem}.
+
+    Thus, actually, calls to \cs{NewGroupedTheorem} will have an underlying
+    \cs{declaretheorem}, but you do not have to bother with this.
+  \end{texnote}
+
+\section{Theorem groups}
 
 \subsection{Defining theorem groups}
 
@@ -181,40 +243,15 @@ of the \meta{theorem family}, which then controls the membership in these groups
     It is subject to an \kw{x}-type expansion prior to being passed further to \pkg{thmtools}.
   \end{texnote}
 
-  As in the \pkg{xparse} package, the behavior of the prefixes is as follows:
-  \begin{description}
-    \item[\cs{NewTheoremGroup}]
+\end{function}
 
-      Defines the theorem group if not defined already.
-      This emits an error in case the theorem group is already defined.
+\subsection{Controlling theorem group precedence}
 
-    \item[\cs{RenewTheoremGroup}]
-
-      Defines the theorem group although defined already.
-      This emits an error in case the theorem group has not been defined yet.
-
-    \item[\cs{ProviedTheoremGroup}]
-
-      Defines the theorem group if it is not defined already.
-      This does not emit an error if the group is already defined
-      (and has no effect in this case).
-      Typically used to ensure that some group exists, whilst not overwriting prior
-      (potentially more custom) definitions of the group.
-
-    \item[\cs{DeclareTheoremGroup}]
-
-      Defines the theorem group in disregard of any
-      existing definitions. An old definition will be overwritten.
-  \end{description}
-
-  \subsection{Controlling theorem group precedence}
-
-  \begin{function}{\DeclareTheoremGroupRule}
+\begin{function}{\DeclareTheoremGroupRule}
     \begin{syntax}
 \cs{DeclareTheoremGroupRule}[\meta{keyname}]%
 \{\meta{theorem group 1}\}\{\meta{relation}\}\{\meta{theorem group 2}\}
     \end{syntax}
-  \end{function}
   
   This declares some relation between the two theorem groups,
   controlling their order of application in case a theorem is member
@@ -240,12 +277,12 @@ of the \meta{theorem family}, which then controls the membership in these groups
   For us, the following list will suffice:
 
   \begin{description}
-    \item[\kw{higher} or \kw{after} or \k{>}]
+    \item[\kw{higher} or \kw{after} or \kw{\string>}]
       
       \meta{theorem group 1} takes precedence over \meta{theorem group 2}.
       Its \kw{prename} is applied after the one of \meta{theorem group 2}.
 
-    \item[\k{lower} or \kw{before} or \k{<}]
+    \item[\kw{lower} or \kw{before} or \kw{\string<}]
 
       \meta{theorem group 2} takes precedence over \meta{theorem group 1}.
       Its \kw{prename} is applied after the one of \meta{theorem group 1}.
@@ -263,6 +300,330 @@ of the \meta{theorem family}, which then controls the membership in these groups
 
 \end{function}
 
+
+\subsection{Inheritance of theorem groups}
+\begin{function}{\AddTheoremGroupParent}
+  \begin{syntax}
+    \cs{AddTheoremGroupParent}\{\meta{theorem group 1}\}\{\meta{theorem group 2}\}
+  \end{syntax}
+  Declares \meta{theorem group 1} to \enquote{inherit} all properties
+  of \meta{theorem group 2}.
+  In other words, \meta{theorem group 2} is a parent of \meta{theorem group 1}
+  in a usual inheritance graph.
+
+  The definitions of the groups themselves are unchanged,
+  but each new theorem defined with \meta{theorem group 1} will also
+  have the properties of \meta{theorem group 2}.
+
+  Inheritance is transitive, when defining a new theorem, we just flatten out the
+  inheritance graph and apply all properties.
+
+  Inheritance is subject to the usual theorem group hierarchies as discussed in \todoref.
+  This can even yield to situations, where \meta{theorem group 1} inherits
+  from \meta{theorem group 2}, but \meta{theorem group 2} overwrites
+  \meta{theorem group 1}.
+\end{function}
+
+\subsection{Appending to theorem groups}
+\begin{function}{\AppendToTheoremGroup}
+  \begin{syntax}
+    \cs{AppendToTheoremGroup}[\meta{keys}]\{\meta{theorem group}\}
+  \end{syntax}
+  Adds the properties given as \meta{keys} to the theorem group.
+  The syntax for the \meta{keys} is the same as in \cs{NewTheoremGroup}.
+\end{function}
+
+\subsection{Default theorem groups}
+
+There are a number of theorem groups that \pkg{group them} will initially declare
+and that have certain special treatment in some places.
+
+\begin{function}{all}
+  Every declared grouped theorem is a member of this group.
+
+  Initially, this group has no effect (i.e.~an empty property list).
+  It can be redefined by the user to alter the behavior of all grouped theorems
+  in a unified way.
+
+  It is the lowest theorem group in the hierarchy by default.
+\end{function}
+
+\begin{function}{starred}
+  This is group that shall represent the standard variant of theorems that
+  are called with a \enquote{*} in the environment name.
+  Theorems of this group are not numbered.
+
+  The user should not add theorems to this group by hand,
+  as this is handled in a unified way by default.
+  \todoref{}
+
+  It is the highest theorem group in the hierarchy by default,
+  except for \cs{unnumbered},
+   with which it has no relation.
+\end{function}
+\addtocounter{footnote}{-1}
+
+\begin{function}{unnumbered}
+  Theorems in this group are not numbered.
+
+ It is the highest theorem group in the hierarchy by default,
+ except for \cs{starred},
+ with which it has no relation.
+\end{function}
+
+The reason for the two groups \kw{starred} and \kw{unnumbered}
+to both exist is that the \kw{starred} group is \emph{meant} to be applied
+to theorems that were called with a \enquote{*} in their name (thus the name),
+whereas the \enquote{unnumbered} group \emph{means} that the environment
+is 'just unnumbered'.
+
+This has two reasons:
+First, this enables more fine-tuning of the behavior of the theorems in post-processing
+of a document.
+Second, more importantly, this distinguishes semantically between the environments
+\kw{theorem} and \kw{theorem*}, even if \kw{theorem} is in the \kw{unnumbered} group.
+
+So assuming that \kw{theorem} is member of the \kw{unnumbered} group, both calls
+
+\begin{verbatim}
+  \begin{theorem}
+    This is not numbered.
+  \end{theorem}
+  \begin{theorem*}
+    This is not numbered.
+  \end{theorem*}
+\end{verbatim}
+
+are defined and will produce the same result by default, but we could still
+change the definition of the \kw{starred} group later to do anything we want.
+
+\begin{texnote}
+  The mentioned hierarchies are kept intact for newly defined theorem groups,
+i.e.~for each new such group, two theorem group rules are created.
+\end{texnote}
+
+\section{Grouped Theorems}
+
+\subsection{Defining grouped theorems}
+
+\begin{function}{\NewGroupedTheorem, \ProvideGroupedTheorem}
+  \begin{syntax}
+    \cs{NewGroupedTheorem}[\meta{keys}]\{\meta{theorem name}\}
+  \end{syntax}
+  This defines \meta{theorem name}  as a new theorem environment.
+  Its properties can be set by the following keys:
+
+  \begin{description}
+
+    \item
+
+      \kw{name} $=$ \meta{displayed name}.
+      If given, this is the displayed name of the environment in the document.
+      If not present, the \meta{theorem name} is also used as the \meta{displayed name}
+      in capitalized form.
+
+    \item
+
+      \kw{group} $=$ \{\meta{clist}\}
+
+      Makes this theorem a member of the listed groups.
+      It will inherit all respective properties of these groups.
+
+      If groups are present more than one time, this has no (additional) effect.
+
+    \item
+
+      \kw{thmtools} = \{\meta{clist}\}
+
+      Passes these option to the \pkg{thmtools} environment that is declared internally.
+    
+  \end{description}
+\end{function}
+
+\begin{function}{\NewGroupedTheorem*,\ProvideGroupedTheorem*}
+  \begin{syntax}
+    \cs{NewGroupedTheorem*}[\meta{keys}]\{\meta{theorem name}\}
+  \end{syntax}
+  Behaves the same as \cs{NewGroupedTheorem},
+  but also adds the theorem to the default \kw{unnumbered} group,
+  thus resulting in the environment not being numbered.
+
+  This is thus equivalent to using \cs{NewGroupedTheorem} and adding the
+  \kw{unnumbered} group.
+\end{function}
+
+\begin{function}{\NewTheorem, \ProvideTheorem}
+  \begin{syntax}
+    \cs{NewTheorem}[\meta{keys}]\{\meta{theorem name}\}
+  \end{syntax}
+
+  This behaves essentially the same as \cs{NewGroupedTheorem},
+  but will define two grouped theorems, namely \meta{theorem name} and \meta{theorem name*}.
+
+  The \meta{theorem name*} environment has the same properties as the \meta{theorem name},
+  but will be member of the \kw{starred} theorem group.
+  It is thus not recommended to call \cs{NewTheorem}
+  with an actual \enquote{*} in the environment name, since both environments
+  will be generated.
+\end{function}
+
+\begin{function}{\NewTheorem*, \ProvideTheorem*}
+  \begin{syntax}
+    \cs{NewTheorem}[\meta{keys}]\{\meta{theorem name}\}
+  \end{syntax}
+  Combines the behavior of \cs{NewGroupedTheorem*} and \cs{NewTheorem}, thus
+  declaring \meta{theorem} to (additionally) be member of the \kw{unnumbered}
+  and \meta{theorem*} to (additionally) be member of the \kw{starred} group.
+
+  As mentioned in \todoref, by default both environments will behave the same.
+\end{function}
+
+\subsection{Defining families of grouped theorems}
+
+\begin{function}{\NewGroupedTheoremFamily, \ProvideGroupedTheoremFamily}
+  \begin{syntax}
+    \cs{NewTheoremFamily}[\meta{keys}]\{\meta{theorem name}\}
+  \end{syntax}
+
+  Defines a family of grouped theorems.
+  The \meta{keys} accept the same arguments as the \cs{NewGroupedTheorem} macro.
+  However, for each \emph{subset} of the given groups,
+  a grouped theorem is defined.
+
+  These grouped theorems are not meant to be accessed directly (but could),
+  so we omit their actual (internal) names here.
+  To call these, some \kw{GroupedTheoremFamilyOptions} have to specified,
+  see \cs{NewGroupedTheoremFamilyOptions}.
+\end{function}
+
+\begin{function}{\NewGroupedTheoremFamily*, \ProvideGroupedTheoremFamily*}
+  Behaves the same as \cs{NewGroupedTheoremFamily}, but also adds each variant
+  to the default \kw{unnumbered} group, thus resulting in the environments not being
+  numbered.
+
+  This is \emph{almost} equivalent to calling \cs{NewGroupedTheoremFamily}
+  with the \kw{unnumbered} group being present, as it does not generate the variants
+  where the \kw{unnumbered} group is not present.
+\end{function}
+
+\begin{function}{\NewTheoremFamily, \ProvideTheoremFamily}
+  This behaves essentially the same as \cs{NewGroupedTheoremFamily},
+  but will add the \kw{starred} group to the list of groups and also generate variants
+  for these.
+
+  It is thus not recommended to call \cs{NewTheoremFamily} with the \kw{starred}
+  group explicitly given, since this is added anyways.
+\end{function}
+
+\begin{function}{\NewTheoremFamily*, \ProvideTheoremFamily*}
+  Combines the behavior of \cs{NewGroupedTheoremFamily*} and \cs{NewTheoremFamily}, thus
+  declaring all variants to (additionally) be member of the \kw{unnumbered}
+  group, and also generates definitions with and without the \kw{starred} group.
+
+  As mentioned in \todoref, by default both environments will behave the same.
+\end{function}
+
+
+\begin{function}{\AddTheoremToGroup}
+  \begin{syntax}
+    \cs{AddTheoremToGroup}\{\meta{theorem group}\}
+  \end{syntax}
+  
+  Means that the current invocation of a theorem family should
+  call the theorem variant with the given group.
+
+  Can only be used in the body of \cs{NewGroupedTheoremFamilyOptions} or similarly.
+\end{function}
+
+\begin{function}
+{
+  \NewGroupedTheoremFamilyOptions, \RenewGroupedTheoremFamilyOptions,
+  \ProvideGroupedTheoremFamilyOptions, \DeclareGroupedTheoremFamilyOptions
+}
+\begin{syntax}
+  \cs{NewGroupedTheoremFamilyOptions}\{\meta{theorem name}\}\{\meta{argument specifiation}\}%
+  \{\meta{selection body}\}
+\end{syntax}
+
+Defines a new environment with options, given by \meta{theorem name}.
+The \meta{argument specification} can be any valid \pkg{xparse} argument specification.
+
+The \meta{selection body} is there to process the options of
+the \meta{argument specification} and select which variant of the \meta{theorem name}
+to enter.
+The arguments are available as usual with \pkg{xparse} by \kw{\#1}, \kw{\#2}, \ldots
+
+The body may also call any number of \cs{AddTheoremToGroup} calls,
+which enables the corresponding groups.
+
+When the environment is called within the document, the options are parsed
+as with \pkg{xpars} and the \meta{selection body} is executed.
+Immediately after, the theorem variant of \meta{theorem name} with the specified groups
+by \cs{AddTheoremToGroup} is called.
+
+At the end of the environment, the \meta{selection body} is executed again and the
+called theorem variant is ended again.
+
+The possible theorem variants that the newly declared environment will call
+\emph{have to be generated subsequently} by a call to the \cs{NewGroupedTheoremFamily}
+function.
+  
+\end{function}
+
+\begin{function}
+  {
+    \NewGroupedTheoremFamilyOptions*, \RenewGroupedTheoremFamilyOptions*,
+    \ProvideGroupedTheoremFamilyOptions*, \DeclareGroupedTheoremFamilyOptions*
+  }
+  \begin{syntax}
+  \cs{NewGroupedTheoremFamilyOptions*}\{\meta{theorem name}\}\{\meta{argument specifiation}\}%
+  \{\meta{selection body}\}
+  \end{syntax}
+  
+  Does the same as \cs{NewGroupedTheoremFamilyOptions},
+  but calls the variants with the additional \kw{unnumbered} group.
+
+  The possible theorem variants have to be generated
+  with the \cs{NewGroupedTheoremFamily*} command before.
+
+\end{function}
+
+\begin{function}
+  {
+    \NewTheoremFamilyOptions, \RenewTheoremFamilyOptions,
+    \ProvideTheoremFamilyOptions, \DeclareTheoremFamilyOptions
+  }
+  \begin{syntax}
+  \cs{NewTheoremFamilyOptions}\{\meta{theorem name}\}\{\meta{argument specifiation}\}%
+  \{\meta{selection body}\}
+  \end{syntax}
+
+  This behaves essentially the same as \cs{NewGroupedTheoremFamilyOptions},
+  but also declares the environment \meta{theorem name*},
+  which behaves the same but calls the theorem variants with the additional \kw{starred}
+  subgroup.
+
+  The possible theorem variants have to be generated with the \cs{NewTheoremFamily}
+  command before.
+  
+\end{function}
+
+\begin{function}
+  {
+    \NewTheoremFamilyOptions*, \RenewTheoremFamilyOptions*,
+    \ProvideTheoremFamilyOptions*, \DeclareTheoremFamilyOptions*
+  }
+
+  Combines the behavior of \cs{NewGroupedTheoremFamilyOptions*} and \cs{NewTheoremFamilyOptions},
+  thus declaring both \meta{theorem name} and \meta{theorem name*} environments,
+  the latter calling the \kw{starred} variants of the theorem family,
+  and both of them calling \kw{unnumbered} variants of the family.
+
+  The possible theorem variants have to be generated with the \cs{NewTheoremFamily*}
+  command before.
+
+\end{function}
+
 %\section{\LaTeX3 interface}
 
 \end{documentation}
diff --git a/src/environments/groupthm.pysty3 b/src/environments/groupthm.pysty3
index 8a9fa6a..b199a37 100644
--- a/src/environments/groupthm.pysty3
+++ b/src/environments/groupthm.pysty3
@@ -393,7 +393,7 @@ __HEADER__(Grouping theorems for easier customization.)
   \add_theorem_to_group:n { #1 }
 }
 
-\DeclareDocumentCommand{ \DeclareTheoremVariants }{ m m m }
+\NewDocumentCommand{ \DeclareTheoremVariants }{ m m m }
 {
   \new_theorem_variant_parser:nnn { #1 } { #2 } { #3 }
 }
@@ -430,7 +430,7 @@ __HEADER__(Grouping theorems for easier customization.)
   % TODO
 }
 
-\DeclareDocumentCommand{\GenerateDefaultTheoremVariants}{ O{} m }
+\NewDocumentCommand{\GenerateDefaultTheoremVariants}{ O{} m }
 {
   \generate_standard_theorem_variants_from_keys:nn { #2 } { #1 }
 }
@@ -446,6 +446,11 @@ __HEADER__(Grouping theorems for easier customization.)
   thmtools = { numbered = no }
 ] { starred }
 
+\NewTheoremGroup
+[
+  thmtools = { numbered = no }
+] { unnumbered }
+
 %%
 
 \NewTheoremGroup