Mechanics Questions -- All in.

[KenProspero]

I have a few questions about what to do when someone raises all in, but cannot make a complete raise.

Situation 1. Player 1 bets $10. Player 2 raises to $16 (total, and is all in).

First, my understanding is that since the raise ($6) was more than half of the previous bet, this counts as a raise (for purposes of determining the maximum number of raises). Also, even if no one else raises, Player 1 can re-raise.

When the betting comes to Player 3, what are his options? Call $16 obviously. But if Player 3 wants to raise, would the minimum be $16 + $4 (completing the raise) or $16 + $10 (adding the previous full bet)?

Situation 2. Player 1 bets $10, and Player 2 raises to $14 (total and is all in).

My understanding is that since the all in bet was a raise of at least 1/2 the minimum raise this doesn't count as a raise for purposes of the maximum amount of raises. Also, if no one else raises, Player 1 can call, but cannot raise.

Does anything change from the previous situation with Player 3?

Situation 3. Player 1 bets $10, and Player 3 Bets $15 (total/all in), i.e., exactly 1/2 the minimum raise. Is this considered a Raise, Can Player 1 re-raise if there is no intervening raise?