What does it mean to be downclosed?
I mean closed downwardly—if one is computable, then so is any smaller one. (And so the Church-Kleene ordinal is the set of all computable ordinals.)
What does it mean to be downclosed?
I mean closed downwardly—if one is computable, then so is any smaller one. (And so the Church-Kleene ordinal is the set of all computable ordinals.)