
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
Given $l$ and $m$ are two different lines, and $\alpha$, $\beta$, $\gamma$ are three different planes, consider the following propositions:  
① If $l \perp \alpha$ and $m \subset \alpha$, then $l \perp m$;  
② If $l \parallel \alpha$ and $m \subset \alpha$, then $l \parallel m$;  
③ If $\alpha \perp \beta$ and $\alpha \perp \gamma$, then $\beta \parallel \gamma$;  
④ If $\alpha \perp \beta$ and $l \perp \beta$, then $l \parallel \alpha$.  
Among these propositions, the numbers of all true propositions are.

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