
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Let $A$, $B$, $C$, $D$ be four points in the plane, where $A(1,3)$, $B(2,-2)$, and $C(4,1)$.
1. If $\overrightarrow {AB}=\overrightarrow {CD}$, find the coordinates of point $D$.
2. Let $\overrightarrow {a}=\overrightarrow {AB}$ and $\overrightarrow {b}=\overrightarrow {BC}$. If $k\overrightarrow {a}-\overrightarrow {b}$ is parallel to $\overrightarrow {a}+3\overrightarrow {b}$, find the value of the real number $k$.

Present the answer in LaTex format: \boxed{Your answer}
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