Re: Logical Implication

From: Isaac Morland <isaac(dot)morland(at)gmail(dot)com>
To: Jacob Champion <jacob(dot)champion(at)enterprisedb(dot)com>
Cc: Vik Fearing <vik(at)postgresfriends(dot)org>, Nathan Bossart <nathandbossart(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Logical Implication
Date: 2026-09-29 16:40:42
Message-ID: CAMsGm5fatRFmUrcr9vCp5wHdbg2gTY=Av78sxsuHOxKD9B54uw@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Tue, 29 Sept 2026 at 12:30, Jacob Champion <
jacob(dot)champion(at)enterprisedb(dot)com> wrote:

Either way, you don't really need to convince me; I just wanted to +1
> Nathan's "no associativity" idea and run away. And associative or not,
> IMPLIES is a lot nicer than the NOT-OR construction.
>

Probably good. I can easily imagine myself seeing a IMPLIES b IMPLIES c and
reading (a IMPLIES b) AND (b IMPLIES c) even though I know that's not how
Postgres operators work.

Personally, I currently spell IMPLIES as "<=" which would be about as good
as you could expect, except that the usual mathematical
implication operator visually appears much closer to "=>". Also any NULL
input at all results in NULL output even when interpreting the NULL as
"unknown" would result in a TRUE result.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Rui Zhao 2026-09-29 17:03:39 Re: Extension security improvement: Add support for extensions with an owned schema
Previous Message Greg Burd 2026-09-29 16:31:39 Re: [PATCH] Corruption Issue: Fix missing tts_tid in ExecForceStoreHeapTuple