Timeline for Are "very conservative" connectives already definable?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Mar 19, 2023 at 17:39 | comment | added | Holo | @PeterLeFanuLumsdaine You are correct, I had a small brainfart | |
| Mar 19, 2023 at 16:00 | comment | added | Peter LeFanu Lumsdaine | @Holo: Not unless I’m either mistaken or badly misunderstanding some terminology here? To me, “$\star$ is already definable” means there’s some formula in two propositional variables $M[A,B]$, such that the rules for $\star$ imply that $\varphi \star \psi \dashv \vdash M[\varphi,\psi]$. If there are no rules at all for $\star$, then surely it’s not definable in this sense? | |
| Mar 19, 2023 at 12:33 | comment | added | Holo | @PeterLeFanuLumsdaine doesn't this fall under "already definable over positive logic"? | |
| Mar 19, 2023 at 6:49 | comment | added | Peter LeFanu Lumsdaine | If I’m understanding the question right, there’s a trivial example: a connective with no rules at all. Did you have other constraints in mind to rule out this example? | |
| Mar 18, 2023 at 23:48 | history | edited | Noah Schweber | CC BY-SA 4.0 |
added 1 character in body
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| Mar 18, 2023 at 20:56 | history | asked | Noah Schweber | CC BY-SA 4.0 |