User blog comment:Kyodaisuu/English description of Fish numbers/@comment-1605058-20131102141329/@comment-1605058-20131102165459

What I think we can do, is express FOST formula as a set (e.g. we can encode characters as elements 1,2,3,...,7 and encode sentence as ordered tuple (a1,a2,a3,...,an)) and then create semantics for it. Then some formula will be able to check if given set satisfies FOST formula, another will check if exactly one set satisfies formula, if that set is a number. Then we can easily check how many elements tuple has, thus how long sentence is. We can finally check all the formulas of given length and find which one defines highest number, succesfully recreating Rayo's function within FOST.