I wrote (in another thread, a few seconds ago):
> I grant the Library a promise, "Promise Q", with the following text:
> {{{{
> This promise is irrevocable.
>
> I grant myself a promise, "Awakening", with the following text:
> {{{
> If I am inactive, I become active.
> }}}
> }}}}
"Promise Q" in this message refers to the promise created, and
designated as "Promise Q", in that above-quoted message.
(A reminder: at Agora, attempts to perform IMPOSSIBLE actions fail.)
I take Promise Q from the Library (using the "Any player CAN…"
mechanism in rule 2618).
I transfer Promise Q from myself to Yachay.
I take Promise Q from the Library (using the "Any player CAN…"
mechanism in rule 2618).
I cash Promise Q.
I call for judgement on the statement "Yachay CAN cash Promise Q,
either by directly cashing it, or by transferring it from the Library
to emself and then cashing it."
I call for judgement on the statement "I CAN cash the promise
'Awakening'."
I recommend linked assignment for these two CFJs.
Arguments:
{{{
We haven't had a good paradox attempt in a while, but I think this one
might be an actual paradox in the rules. This all stems from a future
conditional in rule 2618, "Any player CAN take a specified promise from
the Library by announcement, provided e cashes the promise in the same
message.". Because Promise Q's text unambiguously denotes it as
irrevocable, this is the only mechanism available to me to take Promise
Q from the Library.
According to rule 2618, each of the attempt to take a promise from the
Library (i.e. to transfer a promise from the Library to myself – these
are R2577 synonyms) above succeeds if and only if a) Promise Q is in
the Library at the time, and b) Promise Q is cashed in the same
message.
First, let's look at whether the second attempt to take succeeds. It is
clear that if Promise Q is in the Library at the time of the second
attempt to take, then transferring the promise will allow it to be
cashed (it does not specify cashing conditions, so it is trivial that
any cashing conditions it has are unambiguously met). As such, if
Promise Q is in the Library at the time, the transfer will succeed and
the promise will be cashed. Obviously, if Promise Q is not in the
Library, that will cause the transfer to fail (because you cannot
transfer an asset from an entity that does not own it).
What about the first attempt to take? That one succeeds if the promise
will be cashed, which depends on whether or not I have possession of
the promise after the second attempt to take:
- if it fails, then Promise Q will still be in the Library as of the
second attempt to take (because nothing else could have moved it),
so the promise will be cashed, i.e. if it fails, it will succeed;
- if it succeeds, then I will transfer Promise Q to Yachay, meaning
that I then have no mechanism to cash it, i.e. if it succeeds, it
will fail.
The first attempt to take thus produces a paradox: rule 2618 requires
it to succeed if and only if the promise will be cashed in the same
message (because it is unambiguously in the Library before the
attempt); however, it will be cashed in the same message if and only if
it is not successfully taken.
This paradox attempt gets around the various "unambiguously"
requirements in rule 2618 because those only apply to cashing
conditions, expiration conditions, and statements of irrevocability.
The former two do not exist on any of the involved promises, and the
statement of irrevocability is entirely unambiguous (and not directly
involved in the paradox). Rather, the paradox stems from a future
conditional, that does not have any particular heightened requirement
for unambiguity: it's just "provided e cashes the promise in the same
message".
}}}
--
ais523
