https://www.availlang.org/about-avail/documentation/stacks/l...
There is also a strong beginning of a "cookbook" of expressions here:
https://www.availlang.org/about-avail/documentation/expressi...
There's also coverage of a sizable chunk of Avail's type system here:
https://www.availlang.org/about-avail/documentation/type-sys...