From: Andrew Polonsky <andrew....@gmail.com>
To: Homotopy Type Theory <HomotopyT...@googlegroups.com>
Subject: Re: Meta-conjecture about MLTT
Date: Sun, 11 Sep 2016 22:20:09 -0700 (PDT) [thread overview]
Message-ID: <ca38369f-7691-46f7-8d00-2c944ec6e489@googlegroups.com> (raw)
In-Reply-To: <5fb00299-f5c6-c63c-aade-a688ba2e5f4b@googlemail.com>
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>
> The meta-task is to either produce two isomorphic types in an empty
> context, together with a property that one of them provably has but the
> other doesn't, or to show that this is impossible.
>
What do you mean by a "property", exactly?
If you mean a type family, e.g.,
X : U |- P(X) : Type
then a counterexample is
A = Nat x Bool
B = Bool x Nat
P(X) = Id(U;X,A)
Cheers,
Andrew
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next prev parent reply other threads:[~2016-09-12 5:20 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-11 20:47 Martin Escardo
2016-09-11 22:08 ` [HoTT] " Peter LeFanu Lumsdaine
2016-09-11 22:26 ` Martin Escardo
2016-09-12 9:11 ` Thomas Streicher
2016-09-12 5:20 ` Andrew Polonsky [this message]
2016-09-12 5:59 ` [HoTT] " Jason Gross
2016-09-12 9:55 ` Andrew Polonsky
2016-09-12 10:07 ` Andrew Polonsky
2016-09-12 10:35 ` Nicolai Kraus
2016-09-12 10:16 ` Peter LeFanu Lumsdaine
2016-09-12 10:44 ` [HoTT] " Nicolai Kraus
2016-09-12 11:02 ` Andrej Bauer
2016-09-12 11:14 ` Thomas Streicher
2016-09-12 11:23 ` Andrew Polonsky
2016-09-12 11:41 ` Thomas Streicher
2016-09-12 12:47 ` Thomas Streicher
2016-09-12 13:01 ` Martin Escardo
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