Not if you're constraining yourself to parametric polymorphism. In that case the mzero property is pretty significant and comes up a lot. There's this whole di

Not if you're constraining yourself to parametric polymorphism. In that case the mzero property is pretty significant and comes up a lot. There's this whole discussion about "theorems for free" and why these formalisms are quite useful and relevant to languages like Haskell.