Set Theory and Algebra in CS: Introduction to Mathematical Modeling (2013) [pdf]
call me a mathematical hipster (new frameworks etc.) but i could never get into axiomatic set theory. algebra is already boring by virtue of being abstract but then make it even more abstract by dropping all models! at least in algebra you have applications like galois groups, lie algebras, crypto, etc. yes i know that complexity theory is basically in the domain of set theory (complexity hierarchy) but even that was so abstract. so does anyone know any really cool applications of this stuff (just to be clear i don't mean technology i mean concrete theorems).