Il requisito principale per la ricerca binaria di funzionare è che l'array deve essere ordinato.
Fondamentalmente, il "teorema principale" generalizza quel requisito come necessario per la ricerca binaria generalizzata su funzioni invece di matrici. Dall'articolo:
Behind the cryptic mathematics I am really stating that if you had a yes or no question (the predicate), getting a yes answer for some potential solution x means that you'd also get a yes answer for any element after x. Similarly, if you got a no answer, you'd get a no answer for any element before x. As a consequence, if you were to ask the question for each element in the search space (in order), you would get a series of no answers followed by a series of yes answers.