If "saying" refers to an action, and "believing" to a mental state, what is

If "saying" refers to an action, and "believing" to a mental state, what is

If "saying" refers to an action, and "believing" to a mental state, what is "asserting"? It seems to require an action (i.e. you have to say something) and it also seems to require a mental state (you need to believe what is said).

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