
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
There are the following four propositions:
① If $ac > bc$, then $a > b$.
② The negation of the proposition "Triangles with equal areas are congruent".
③ The contrapositive of the proposition "If $m \leq 1$, then the equation $x^2 - 2x + m = 0$ has real roots".
④ The contrapositive of the proposition "If $A \cap B = B$, then $A \subseteq B$".
Among these, the true propositions are.

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