Verbs for subscribing to a proposition [closed]

When A believes that the proposition p is true, we may say

A subscribes to the proposition that ...

Which verbs may replace the italicized expression without altering the meaning of the sentence?

Answers should be either suitable to academic prose or archaic.

Solution 1:

One may espouse or embrace a proposition, particularly if it is a deeply-held belief.

If the person actively supports the proposition, in addition to simply believing it is true, you could also say that they champion, endorse, or advocate it.

Solution 2:

"Believes"!

There is also "accepts", and possibly in some contexts "adopts".