As usual in functional programming, read from right to left (or bottom to top):

The map changes the sentences to arrays of arrays. Each such an array has two elements: the word to sort on and the original sentence.

sort just sorts the arrays according to their first element, i.e. the sort word.

map transforms the arrays back to sentences.

لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^3: ordering array of sentences by choroba
in thread ordering array of sentences by welle

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