A list of values of type 'a.

return a makes a singleton list with the element a.

l >>= f applies the function f to all elements of the list l and concatenates all lists.

f >=> g composes the two monadic functions f and g.

flst <*> lst is equivalent to flst >>= fun f -> map f lst i.e. it maps all functions contained in flst over the list lst and then concatenates the results.

join is the same as concat.

find p l finds an element e in the list l which satisfies p e.

ith_strict n list returns the nth element of the list. Precondition: list has at least n + 1 elements.

ith_strict n list returns the nth element of the list if the list is long enough. Otherwise None is returned.

append a b prepends the lists a in front of the list b. Synonym a @ b.

concat ll concatenates all lists contained in the list of lists ll.

Transform a list of pairs into a pair of lists.

rev a reverses the list a.

rev_append a b prepends the lists rev a in front of the list b.

map_and_filter f list maps the list with f and removes the element for which f e = None.

split_at p lst scans the list until it finds the first element satisfying p and returns the prefix and the remainder starting at the encountered element.

Monadic list folding