IMHO the benefit of fp is it's easier to prove things. The downside is that it's more work: being able to show you've done something correctly is extra work on

IMHO the benefit of fp is it's easier to prove things. The downside is that it's more work: being able to show you've done something correctly is extra work on top of the actual doing of it correctly. There's a point of view that if you haven't done it correctly, you haven't done it at all. There's another point of view that you just fix bugs as they found.