Ok, so I started learning lua today 
I want to create Chinese alternate UA, Mandate of Heaven:
"Each time you gain 10 citizen in cities or settle a new city, receive science and culture boost; Great Generals are stronger. If happiness drops below zero, Mandate is lost and rebels start appearing. -20% strenght against barbarians."
I figured out part with "tenth citizen", thanks to Leugi's Aymara which has something similiar
and I guess (PlayerCityFounded) is proper command for "new city settled" ; also I want to experiment with science/culture boost a bit.
However I have two other questions about lua:
1) How make something like that:
if X or Y
then Z
2) How to make rebels appearing below 0 happiness (only for China) and -20% against rebels (only for China)? I didn't find any mods with something similar, something dealing with barbs.

I want to create Chinese alternate UA, Mandate of Heaven:
"Each time you gain 10 citizen in cities or settle a new city, receive science and culture boost; Great Generals are stronger. If happiness drops below zero, Mandate is lost and rebels start appearing. -20% strenght against barbarians."
I figured out part with "tenth citizen", thanks to Leugi's Aymara which has something similiar

However I have two other questions about lua:
1) How make something like that:
if X or Y
then Z
2) How to make rebels appearing below 0 happiness (only for China) and -20% against rebels (only for China)? I didn't find any mods with something similar, something dealing with barbs.