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Timeline for Very dependent functions

Current License: CC BY-SA 4.0

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Dec 17, 2022 at 15:32 comment added James Deikun That's indeed the most troubling part of these rules. I don't have a full proof or prototype, but considering the occurrences of $f$ have to be structurally decreasing applications, as long as there's a substitution algorithm for the external form this should work out. A really precise specification of this would have a special part of the context for 'conjectured' $f$ of this sort, and maybe even a special judgement form and a copy of the elimination rule therein. (I've also tried to find some kind of alternate rules that have logical harmony but this is still the best I've come up with.)
Dec 15, 2022 at 18:27 comment added Mike Shulman I have trouble understanding how rules like this would work in practice, and how we can believe that they will be well-behaved. Generally I think of a typechecking algorithm as taking some surface syntax (unchecked term) as input and producing some internal values (checked term) as output. The types appearing in a context, and the type being checked against, are always internal values. But here, in {}-form, you are placing $\{f\mid \Delta \to B\}$ in the context before you've finished typechecking it, so you don't have an internal value to put there. The other rules are similar.
Sep 21, 2022 at 11:55 comment added James Deikun @AndrejBauer Edited, thanks.
Sep 21, 2022 at 11:51 history edited James Deikun CC BY-SA 4.0
Fixed problems spotted by Andrej Bauer ... thanks!
Sep 21, 2022 at 8:50 comment added Andrej Bauer The conclusion of {}-form seems to have an extraneous "$f :$" in the conclusion, and something is wrong with the context in the conclusion of {}-intro.
S Sep 19, 2022 at 22:49 review First answers
Sep 24, 2022 at 11:51
S Sep 19, 2022 at 22:49 history edited James Deikun CC BY-SA 4.0
Added extra type condition to {}-elim to make the assumption in {}-form safer
Sep 19, 2022 at 17:46 history edited James Deikun CC BY-SA 4.0
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Sep 19, 2022 at 17:44 history edited James Deikun CC BY-SA 4.0
added 27 characters in body
Sep 19, 2022 at 17:40 history edited James Deikun CC BY-SA 4.0
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Sep 19, 2022 at 17:39 history edited James Deikun CC BY-SA 4.0
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S Sep 19, 2022 at 17:36 review First answers
Sep 19, 2022 at 22:33
S Sep 19, 2022 at 17:36 history answered James Deikun CC BY-SA 4.0