XPost: comp.theory, comp.prolog, sci.math   
   From: polcott333@gmail.com   
      
   On 12/5/2025 4:33 AM, Tristan Wibberley wrote:   
   > On 04/12/2025 08:58, Mikko wrote:   
   >> Tristan Wibberley kirjoitti 4.12.2025 klo 4.32:   
   >>> On 30/11/2025 09:58, Mikko wrote:   
   >>>   
   >>>> Note that the meanings of   
   >>>>    ?- G = not(provable(F, G)).   
   >>>> and   
   >>>>    ?- unify_with_occurs_check(G, not(provable(F, G))).   
   >>>> are different. The former assigns a value to G, the latter does not.   
   >>   
   >>> For sufficiently informal definitions of "value".   
   >>> And for sufficiently wrong ones too!   
   >>   
   >> It is sufficiently clear what "value" of a Prolog variable means.   
   >   
   > I didn't read that as a use of prolog terminology. So I went and   
   > understood why I didn't bring such to mind. It's because a "value" isn't   
   > "assigned" to A by that (see my paragraph below for the most peculiar   
   > thing that I would concede if my life depended on it, but my life is   
   > more likely to depend on not conceding it).   
   >   
      
   int main()   
   {   
      bool Sentence = !(Sentence); // Liar Paradox in C++   
      return 0;   
   }   
      
   What value does Sentence have?   
      
   Prolog proves that   
   ?- G = not(provable(F, G)).   
   Is stuck in an infinite loop thus never has a value.   
      
   > The only extent to which "?- A = B." for nonvar(B) has something like   
   > assignment of a value to A is that there's might be a program address   
   > (Dijkstra-oriented notion as one would perceive in a prolog debugger)   
   > which differs from its predecessor by instantiation alone including in   
   > ones consisting of just one unification. Whether that happens is   
   > contingent because it's operational and there's no effect in the   
   > language for that specific example. The statement doesn't have to end up   
   > with more than one program address (being both the first and the last   
   > address when permissible syntactic transformations are applied). I don't   
   > think it's reasonable to call that assignment of a value, not even for   
   > lots of very ordinary statements because it's merely contingently   
   > equivalent "in effect" to assignment in other languages and not part of   
   > the /meaning/ of the statement specifically; nor is it part of the   
   > meaning of =/2 generally.   
   >   
      
      
   --   
   Copyright 2025 Olcott   
      
   My 28 year goal has been to make   
   "true on the basis of meaning" computable.   
      
   This required establishing a new foundation   
   for correct reasoning.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)