diff --git a/electives/amr/autonomous-mobile-robots-cheatsheet.pdf b/electives/amr/autonomous-mobile-robots-cheatsheet.pdf
index 97f8a1b..3a11aa5 100644
Binary files a/electives/amr/autonomous-mobile-robots-cheatsheet.pdf and b/electives/amr/autonomous-mobile-robots-cheatsheet.pdf differ
diff --git a/electives/amr/parts/01_kinematics/01_forward.tex b/electives/amr/parts/01_kinematics/01_forward.tex
index 252748a..07054c2 100644
--- a/electives/amr/parts/01_kinematics/01_forward.tex
+++ b/electives/amr/parts/01_kinematics/01_forward.tex
@@ -8,5 +8,8 @@ $ \begin{bmatrix}
         L_1 \sin(\theta_1) + L_2 \sin(\theta_1 + \theta_2)
     \end{bmatrix}$\\
 }
-With workspace (pos) $W$ for $\theta_1, \theta_2 \in [-\pi, \pi]$
-% TODO: Example? (w02s42 possibly)
+Similar for $n$R sys (more angles). Wspc $W$ $\theta_1, \theta_2 \in [-\pi, \pi]$.
+Last dim may be sum of angles. Jacobian: see \ref{sec:ms-lin}
+
+\shortdefinition[Singularity] Loss of deg of Freed. $\det(\mat{J}(\vec{\theta})) = 0$
+% TODO: Determinant computation
diff --git a/electives/amr/parts/03_multi-sensor-estimation/00_linearization.tex b/electives/amr/parts/03_multi-sensor-estimation/00_linearization.tex
index 8cfc94e..b3c8e4a 100644
--- a/electives/amr/parts/03_multi-sensor-estimation/00_linearization.tex
+++ b/electives/amr/parts/03_multi-sensor-estimation/00_linearization.tex
@@ -1,4 +1,5 @@
 \subsection{Linearization}
+\label{sec:ms-lin}
 $\vec{f}(\vec{x}) \approx \vec{f}(\vec{\overline{x}}) + \mat{J}_{\vec{f}} \big|_{x = \overline{x}}(\vec{x} - \vec{\overline{x}})$, $f'$, no vec in 1D; $\vec{\overline{x}}$ lin. p.
 
 \shortdefinition[Jac.] $\mat{J}_{\vec{f}}$ rows for eq of $\vec{f}$ cols for vars of each eq.