Returns true if and only if there exists an element for which the provided
function evaluates to true. This is a short-circuiting operation.
Returns true if and only if the provided function evaluates to true for all
elements. This is a short-circuiting operation.
Returns the sum of f i for i in the container
Returns a min (resp max) element from the collection using the provided cmp
function. In case of a tie, the first element encountered while traversing the
collection is returned. The implementation uses fold so it has the same complexity
as fold. Returns None iff the collection is empty.