'Epistemic->Content' transformation via enrichment

Hi there,
Can someone describe to me transformation process of epistemic conditional into content conditional via enrichment?

e.g:
If John went to that party, (then) he was trying to infuriate Miriam.

Thanks for help!

See example (4) on page 150 here.

thanks!
just to make sure,
example form my previous post transformed into content conditional would look sth like this:

If it is true that John went to that party, then I conclude he was trying to infuriate Miriam.

cheers!

Right. "I concluded."