Background information: Combinatory logic on Wikipedia
Basically it is a model of computation closely related to lambda calculus, but using a fixed set of combinators instead of lambda abstraction. The most prominent form of this is SKI (or SK) combinator calculus, which is extensionally equivalent to lambda calculus and therefore is Turing-complete (essentially a Turing tarpit).
I've identified nine challenges that are directly related to combinatory logic.
- Four challenges mentioning "SKI calculus"
- Four challenges mentioning "combinatory"
- One that is essentially BC calculus golf
Some of these are tagged lambda-calculus, but it isn't directly relevant to lambda calculus per se. So, can we have a separate tag for combinatory logic?