TraderMC, gaps are all of the above.Gaps themselves do nothing...

TraderMC, gaps are all of the above.
Gaps themselves do nothing to the share price, no matter how they are defined.
What matters is what people think of the gaps. As each trade is based on the emotional and logical processes of a person (except bots, but that is another story). Therefor 1000 different trades and the resulting price is the overall affect of these thoughts.

So Gaps influence the trading decisions as many people punt on the idea that they will be closed, statistically most of them do, eventually (could be years).
As such, if you want to use Gaps to help trade you need to be aware of the different definitions that people use.

Perhaps this is why you are confused, trying to seek out the one rule when the answer is that there are multiple definitions and all are correct as they all influence some portion of the daily trades.