(() => {
    'use strict';

    // squared :: Num a => a -> a
    const squared = x => Math.pow(x, 2);

    // sum :: (Num a) => [a] -> a
    const sum = xs => xs.reduce((a, x) => a + x, 0);

    // sumOfSquares :: Num a => [a] -> a
    const sumOfSquares = xs => sum(xs.map(squared));

    // sumOfSquares2 :: Num a => [a] -> a
    const sumOfSquares2 = xs =>
        xs.reduce((a, x) => a + squared(x), 0);

    return [sumOfSquares, sumOfSquares2]
        .map(f => f([3, 1, 4, 1, 5, 9]))
        .join('\n');
})();