# [Haskell], 39 bytes <!-- language-all: lang-hs --> (a:t)#n=any(==n)(map(a+)t)||t#n _#n=1<0 [Try it online!] Example usage: `[1,3,2,5] # 3`. Returns `True` or `False`. [Haskell]: https://www.haskell.org/ [Try it online!]: https://tio.run/nexus/haskell#NYpBCsIwEEX3niIwmwS/4CRpFTFH8AQhSJZddCiSTaF3j0NQ/uq997utj@ZIUpXdpiTOrnWz9eyaO45Gcnpr4@e1r3URk4zWl9k@izSTc0DEVGiGyQyPgZgLMauJ8AF3vkVEjwsXijx@/4VCQYX/4RTg9TPMmELpXw "Haskell – TIO Nexus" ____ **40 byte alternative** f(a:t)=map(a+)t++f t f e=e (.f).any.(==)