What?? edit

P implies Q implies R.

Does this mean

(P implies Q) implies R

or

P implies (Q implies R)

??

Which is it?? Michael Hardy (talk) 04:35, 18 February 2012 (UTC)Reply

The latter, according to the quoted source. -- Jitse Niesen (talk) 14:53, 18 February 2012 (UTC)Reply

Proof edit

I removed the proof (reproduced below) because it seems to prove the same thing as it assumes at the start.

Proposition Derivation
  Given
  Material implication
  Material implication
  de Morgan's law
  Material implication
  de Morgan's law
  Material implication

-- Jitse Niesen (talk) 14:53, 18 February 2012 (UTC)Reply

Proposal to merge Import–export (logic) into Exportation (logic) edit

Import–export (logic) and Exportation (logic) both discuss importation and exportation, and belong to Category:Theorems in propositional logic as well as Wikipedia:WikiProject Philosophy.

Import–export (logic) focuses on discussion of the topic, including how the rule does not necessarily hold in a non-classical logic. Exportation (logic) is focused on the rule's technical definition and proof.

--Luke1337 (talk) 10:12, 4 March 2023 (UTC)Reply

Closing, given that there is no case made for the proposal, and there has been no support over many months. That the articles are related isn't in doubt, but the reason for merging them hasn't been explicitly made. Klbrain (talk) 08:25, 10 November 2023 (UTC)Reply