I think I recall reading somewhere that you only need first-order logic to define Turing machines and computer programs in general, which seems to suggest that “not expressible in first order logic” means “uncomputable”… I could just be really confused about this though...
Anyway, for some reason or other I had the impression that “not expressible in first order logic” is a property that might have something in common with “hard to explain to a machine”.
I think I recall reading somewhere that you only need first-order logic to define Turing machines and computer programs in general, which seems to suggest that “not expressible in first order logic” means “uncomputable”… I could just be really confused about this though...
Anyway, for some reason or other I had the impression that “not expressible in first order logic” is a property that might have something in common with “hard to explain to a machine”.