Skip to main content
18 events
when toggle format what by license comment
Jun 16, 2020 at 10:30 history edited CommunityBot
Commonmark migration
Dec 18, 2018 at 12:11 history edited Patrick Browne CC BY-SA 4.0
deleted 14 characters in body
Dec 16, 2018 at 11:11 history edited Patrick Browne CC BY-SA 4.0
added 2 characters in body
Dec 16, 2018 at 10:51 history edited Patrick Browne CC BY-SA 4.0
added 81 characters in body
Dec 14, 2018 at 11:33 history edited Patrick Browne CC BY-SA 4.0
added 14 characters in body
Dec 13, 2018 at 20:01 history edited Patrick Browne CC BY-SA 4.0
added 28 characters in body
Dec 13, 2018 at 19:40 history edited Patrick Browne CC BY-SA 4.0
added 3 characters in body
Dec 13, 2018 at 19:24 history edited Patrick Browne CC BY-SA 4.0
added 773 characters in body
Dec 7, 2018 at 11:05 comment added xuq01 I have no doubts that the theorems are true. But you will want to prove if the output of your program satisfies your theory using either an automated theorem prover or a proof assistant.
Dec 7, 2018 at 9:37 history edited Patrick Browne CC BY-SA 4.0
deleted 53 characters in body
Dec 7, 2018 at 9:32 comment added Patrick Browne @xuq01 I have already used an automatic theorem prover to prove the theorems.
Dec 7, 2018 at 9:29 comment added Patrick Browne @Derek Elkins Your comment identifies my confusion on the relation between a logical theory (in FOL) and Haskell program purporting to represent that theory. From my previous post on this topic the execution of a Haskell program does not count as a proof, from this post my code does not represent a decision procedure.
Dec 7, 2018 at 9:23 history edited Patrick Browne CC BY-SA 4.0
added 405 characters in body
Dec 7, 2018 at 9:10 comment added Patrick Browne @stewbasic If I omit the False equations the theorems will not run. So, the False equations are included for operational rather than purely logical reasons.
Dec 6, 2018 at 22:02 comment added Derek Elkins left SE A decision procedure for a formula $\varphi$ (or, alternatively, set $S$) takes as input a term $x$ and outputs whether $\varphi(x)$ (or $x\in S$) holds. It doesn't make sense to ask if something is a decision procedure for a theorem. You are also adding a closed world assumption though that doesn't impact the particular statements presented as theorems.
Dec 6, 2018 at 21:50 comment added stewbasic In belongs (_,_) = False and lieOn (_,_) = False you seem to be assuming that a city can only belong to one country and only lie on one river. However all of the theorems can be proven without this assumption.
Dec 6, 2018 at 21:08 comment added xuq01 I am tempted to say "prove it in Coq..."
Dec 6, 2018 at 19:28 history asked Patrick Browne CC BY-SA 4.0