***** NOT A TEACHER *****
I have found some information that I am delighted to share with anyone who is interested in this topic.
1. Some sources simply say that an infinitive may be joined to a conjunction:
"He knows better than [conjunction] to lend her money." [ infinitival phrase]
2. Some sources say that it must be some kind of ellipsis.
a. Some sources think that it may be a shorter way of saying "He knows better than [it is] to lend her money."
b. Some sources think that it may be a shorter way of saying "He knows better than to lend her money [is good]."
Of course, I do not know who is correct.
I am eager to know what others think.
Interested in Language