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Sep 17 2019 08:10pm
Show a set which satisfies the following form:

A = {A}


will pay 10 fg
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Sep 18 2019 01:49pm
Try to write a set A which satisfies the following form: A = {A}. This type of definition should be avoided, even if in this case we can define a (weird) set which satisfies the form A = {A}.
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Sep 18 2019 02:35pm
Russell's type theory forbid to consider that a set may be a subset of itself, to avoid Russell's paradox.

What are you working on ?
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Sep 18 2019 03:30pm
Quote (feanur @ Sep 18 2019 04:35pm)
Russell's type theory forbid to consider that a set may be a subset of itself, to avoid Russell's paradox.

What are you working on ?


Yes, but still need to define a set for my discrete math homework
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Sep 20 2019 02:38am
Then let :
A0 = ∅
A1 = {A0} = {∅}
A2 = {A1} = {{∅}}
A3 = {A2}
...

and imagine what A∞ looks like.
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Posts: 30,945
Joined: Apr 13 2008
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Sep 20 2019 02:02pm
Quote (feanur @ Sep 20 2019 04:38am)
Then let :
A0 = ∅
A1 = {A0} = {∅}
A2 = {A1} = {{∅}}
A3 = {A2}
...

and imagine what A∞ looks like.


Thats works.
10 fg winner

A = {x | x ∈ A}
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