diff --git a/trees/latex-preamble.tree b/trees/latex-preamble.tree
index 1a5d4d2..1c9a32c 100644
--- a/trees/latex-preamble.tree
+++ b/trees/latex-preamble.tree
@@ -100,6 +100,14 @@
 	spacebelow=0pt
 ]{def}
 
+\declaretheoremstyle[
+	headfont=\bfseries\sffamily,
+	bodyfont=\normalfont, %\small, %\sffamily,
+	spaceabove=0pt,
+	spacebelow=0pt,
+    numbered=no
+]{def*}
+
 \theoremstyle{definition}
 % \declaretheorem[style=thmblackbox,name=Definition,numberwithin=subsection]{definition}
 \declaretheorem[style=thmbluebox,name=Theorem,numberwithin=subsection]{theorem}
@@ -113,6 +121,7 @@
 % \newtheorem{claim}[theorem]{Claim}
 % \newtheorem{definition}[theorem]{Definition}
 \declaretheorem[style=def,name=Definition,sibling=theorem]{definition}
+\declaretheorem[style=def*,name=Definition]{definition*}
 % \newtheorem{fact}[theorem]{Fact}
 % \newtheorem{abuse}[theorem]{Abuse of Notation}
 
diff --git a/trees/uts-0002.tree b/trees/uts-0002.tree
index aa303c5..564cf6a 100644
--- a/trees/uts-0002.tree
+++ b/trees/uts-0002.tree
@@ -12,7 +12,7 @@
 
 \minitex{
 
-\begin{definition}[Spin group]
+\begin{definition*}[Spin group]
 
 The Pin group of $(V, q)$ is the subgroup $\operatorname{Pin}(V, q)$ of $P(V, q)$ generated by the elements $v \in V$ with $q(v) = \pm 1$.
 
@@ -22,7 +22,7 @@ $$
 \operatorname{Spin}(V, q)=\operatorname{Pin}(V, q) \cap \mathrm{Cl}^0(V, q)
 $$
 
-\end{definition}
+\end{definition*}
 
 }