comma before/after infinitive marker: to, acting jointly, certify

Alan and Will were authorized to, acting jointly or individually any of the two, certify the act.

Alan and Will were authorized , acting jointly or individually any of the two, to certify the act.

Alan and Will were authorized to certify , acting jointly or individually any of the two, the act.

Whisch one is the correct?

None of them are great, in my opinion. :(

I would say the first one is incorrect. Of the remaining two, the second one is less objectionable than the third, in my view.

I would rewrite it as:

Acting jointly or individually, Alan and Will were authorized to certify the act.

OR


Alan and Will were authorized to certify the act, either jointly or individually.

The middle one would be O.K. without the redundant "any of the two" (there are only two people), but I would put the dependent clause up at the front:

"Whether acting individually or jointly, both Alan and Will were authorized to certify the act."

Thanks, Alan, this one is the one that conveys the real meaning:
Alan and Will were authorized to certify the act, either jointly or individually.

The third one is ungrammatical because something separates the verb from its object: :cross:'certify X the act'. Be careful about this - in French I know this is a favourite position for an adverb, so I'd guess it is in your native Spanish too; it's usually wrong in English. The others just sound bad, and your later rewriting, with the 'either' phrase at the end, is much better.

This is an excellent example of why infinitives should not be split. It's one thing to drop a single adverb into an infinitive; putting an eight-word phrase between "to" and the verb just shatters it. For that reason, I would say that none of the three sentences is "correct." And they are all terrible style, the kind of thing that muddled lawyers write not only to confuse non-lawyers, but to confuse themselves.

Follow Yankee's advice to get rid of the unnecessary "any of the two" and get the resulting "acting jointly or individually" out of the infinitive "to certify."

My recommendation, keeping as much of the original verbiagae as possible:

Alan and Will were authorized to certify the act, acting jointly or individually.

There should be never be a space between a word and a comma that follows it.

Thank you all for you expertise in the matter.