intuition

Putting $$s in the middle of an `equation` environment: why doesn't Latex complain?

I was surprised that the Latex code from a recent question didn't throw up any errors, and even more surprised on further investigation, that Crowley's explanation seems to be true. My intuition about the \begin{equation} ... \end{equation} code is clearly off, what's really going on? Consider this, slightly adapted code: \begin{equa...

Explanation of Monad laws

From a gentle introduction to Haskell, there are the following monad laws. Can anyone intuitively explain what they mean? return a >>= k = k a m >>= return = m xs >>= return . f = fmap f xs m >>= (\x -> k x >>= h) = (m >>= k) >>= h Here is my attempted explanation: We expect the return function ...