Hi all. I have two questions. I know what hammer-on's and pull-off's are, but there are two things that I don't understand.

First: When there are two pull-off's in a row like this: 19p15p12

Link: http://www.ultimate-guitar.com/tabs/b/black_sabbath/paranoid_solo_tab.htm

In this case do you play the string at 19th fret then pull-off to 15th string, then after that play the 15th string again and pull-off to 12th string?
Or do you play the 19th string, then pull-off to 15th string, then pull-off to 12th string? (In this case you only play the string once, meaning that you'd have to have 3 fingers at the fretboard when you play the string)

Second: When there's a hammer-on that doesn't show where you hammer: ---9h---

Link: http://www.ultimate-guitar.com/tabs/b/black_sabbath/iron_man_tab.htm

Well, yeah, does that just mean that you hammer the string without actually playing it before?

I hope someone can help me
Thanks in advance
From what I know:

For the first example, you'd have to have 3 fingers on the fretboard.
For the second, that's a mistake in the tab I believe.
the first could also be tapped but it doesn't say so, so i guess no. 3 fngrs on the fretboard it s then.
Alright, thanks for the help.
It just seems quite hard to have 3 fingers on the fretboard when it's 19p15p12 (They are quite far from each other). I guess it just needs practice
If you are having trouble keepig 3 fingers on the fretboard at once on far apart frets you can just play it by having a finger (little finger) on the 19 and one on the 15 (middle finger) with your middle finger facing up the fretboard, pressing the string down with the side, then after you pick the string roll your middle finger along then place your index finger on the 12 before lifting the middle finger, you can almost double the distance your hand can span that way.