module CurryLab where

-- Meta comment: For each function that outputs multiple answers, the order of
-- the answers does not matter, e.g., it is up to you which answer to output
-- first.


-- [2 marks]
-- Integers from 0 to n-1. If n <= 0, there is no answer.
below :: Int -> Int
below = error "TODO"


-- [4 marks]
-- Sublists of xs. This means:
-- If you pretend xs to be a [multi]set, then a sublist is like a subset,
-- but furthermore, its elements follow the same order as in xs.
--
-- Example: The sublists of [0,1,2] are:
-- [], [0], [1], [2], [0,1], [0,2], [1,2], [1,2,3]
sublist :: [a] -> [a]
sublist = error "TODO"


-- We are given a child->parent relation as a non-deterministic function from
-- children to parents. E.g., George's parents are Elizabeth and Henry.
parent :: String -> String
parent "George" = "Elizabeth" ? "Henry"
parent "Fiona" = "Elizabeth" ? "Henry"
parent "Mary" = "Theresa" ? "Henry"
parent "Frederick" = "Theresa" ? "Francis"


-- [4 marks]
-- Find the siblings of the input person.
-- Definition: y is a sibling of x iff x/=y and someone is a parent of both.
-- Duplicate answers are OK, e.g., sibling "George" gives "Fiona" twice because
-- of Elizabeth and Henry.
sibling :: String -> String
sibling = error "TODO"