atom koan enlightened
boolean expression koan complete
string koan theorized
binary koan complete
pattern-koan-match complete

This was easy because of the pattern matching in #prolog
guards koan'd
lists koan'd

There is a funky thing here. What Erlang calls "key" is what most
other languages call "value". But this may just be something that
has to do with its pattern matching.
lists comprehended

Comprehensions always return lists