Sujet : Re: Advent of Logic 2024: Friendly Reminder (Re: Advent of Logic 2024: Specification and Deadline)
De : janburse (at) *nospam* fastmail.fm (Mild Shock)
Groupes : sci.logicDate : 24. Dec 2024, 00:09:57
Autres entêtes
Message-ID : <vkcqk5$19bn1$1@solani.org>
References : 1 2 3
User-Agent : Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 SeaMonkey/2.53.19
Ok, I made a solution for Weekend 3,
first I made minimal logic. I opted for
Lambda Expressions with de Brujin indexes:
/* 4 positive test cases */
% ?- between(1,13,N), search(typeof(X, [], ((a->a)->(a->a))), N, 0).
% N = 2,
% X = lam((a->a), 0) .
% ?- between(1,13,N), search(typeof(X, [], (a->((a->b)->b))), N, 0).
% N = 5,
% X = lam(a, lam((a->b), 0*1)) .
% ?- between(1,13,N), search(typeof(X, [], (a->(b->a))), N, 0).
% N = 3,
% X = lam(a, lam(b, 1)) .
% ?- between(1,13,N), search(typeof(X, [], ((a->(a->b))->(a->b))), N, 0).
% N = 7,
% X = lam((a->a->b), lam(a, 1*0*0)) .
For example the 2nd solution with de Brujin indexs
can be read without de Brujin indexes as follows:
λx:a.λy:(a->b).(y x) : (a->((a->b)->b))
https://gist.github.com/Jean-Luc-Picard-2021/db6f71f66781838c98ee8b828eb5b9c2#file-minimal-pMild Shock schrieb:
Hi,
Friendly Reminder that the Deadline 24. December 2024
is approaching. Please be aware that Weekend 3 asks for
Natural Deduction, where (E⊃) and Modus Ponens are synonymous:
/* Scope of Weekend 3 */
C, X ⊢ Y
-------------- (I⊃)
C ⊢ X ⊃ Y
C ⊢ X C ⊢ X ⊃ Y
--------------------- (E⊃) /* Also known as Modus Ponens */
C ⊢ Y
Simply Types and its Curry Howard is primarily defined
for Natural Deduction. Extracting Lambda Experessions
from Non-Natural Deduction is a little bit more complicated.
So Weekend 3 is NOT for Sequent Calculus:
/* Not Scope of Weekend 3 */
C, X ⊢ Y
-------------- (R⊃)
C ⊢ X ⊃ Y
C ⊢ X C, Y ⊢ Z
--------------------- (L⊃)
C, X ⊃ Y ⊢ Z
Bye
Mild Shock schrieb:
Specification:
>
>
Weekend 2:
-----------
- Input = Atom % Propositional variable
| Input -> Input % Implication
>
- Output = B % B Axiom Schema
| C % C Axiom Schema
| I % I Axiom Schema
| (Output Output) % Modus Ponens
>
Weekend 3:
-----------
- Input = Atom % Propositional variable
| Input -> Input % Implication
>
- Output = Variable % Repetition
| λVariable.Output % Assumption & Detachment
| (Output Output) % Modus Ponens
>
>
Deadline:
>
24. December 2024
>