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diff --git a/utility.hs b/utility.hs
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+module Utility where
+
+import Data.List
+
+--if any of the predicates returns true, options returns true
+options :: [a -> Bool] -> a -> Bool
+options l x = any id [f x | f <- l]
+
+fixpoint :: (Eq a) => (a -> a) -> a -> a
+fixpoint f x = let fx = f x in if fx == x then x else fixpoint f fx
+
+setcompareBy :: (a -> a -> Bool) -> [a] -> [a] -> Bool
+setcompareBy _ [] [] = True
+setcompareBy _ [] _ = False
+setcompareBy _ _ [] = False
+setcompareBy p a@(x:xs) b = length a == length b && setcompareBy p xs (deleteBy p x b)
+
+deleteIndex :: Int -> [a] -> [a]
+deleteIndex 0 (_:xs) = xs
+deleteIndex i (x:xs) | i > 0 = x : deleteIndex (i-1) xs