[epgui]

> What on earth makes you convinced that a monad can be implemented in Excel

True monads can't even be implemented in Haskell. But if we're being practical, you can totally implement monad-like things in Excel. It's almost impossible not to implement monad-like things when building anything non-trivial.

[kfixjviv]

I don't think making this claim is helpful. Monads aren't found everywhere in code. Solving a problem which could be solved by monads doesn't automatically lead to code that works in a monad-like way, not in any meaningful sense.

[epgui]

> Monads aren't found everywhere in code.

I completely disagree... The distinction is simply that they're usually ad-hoc and not formalized, mainly because the author didn't know what they were writing and was reinventing the wheel.