These look almost the same, but they are different constructs. \hinline{where} is bound to the pattern matching \hinline{f x =} and may also have access to parts of a function that are not syntactically expressions, e.g.: \begin{haskellcode} f x | cond1 x = a | cond2 x = g a | otherwise = f (h x a) where a = w x \end{haskellcode} While that is not possible with \hinline{let}, which is an actual expression and can be used whenever expressions are allowed (e.g. inside \emph{Monads}, we'll know more about these in a few weeks). \vspace{\baselineskip} \\ There are a few more intricacies, but most of the time this is just style consideration:\\ \url{https://wiki.haskell.org/Let_vs._Where} \pause \vspace{\baselineskip} \\ How would we have to rewrite the function in order to use \hinline{let}?