“a†is an element of a set of a set of “a�
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I'm having a hard time conceptualizing what this means:
$a in a$
Is this saying that the a is an element of the set of set a?
elementary-set-theory
add a comment |Â
up vote
5
down vote
favorite
I'm having a hard time conceptualizing what this means:
$a in a$
Is this saying that the a is an element of the set of set a?
elementary-set-theory
add a comment |Â
up vote
5
down vote
favorite
up vote
5
down vote
favorite
I'm having a hard time conceptualizing what this means:
$a in a$
Is this saying that the a is an element of the set of set a?
elementary-set-theory
I'm having a hard time conceptualizing what this means:
$a in a$
Is this saying that the a is an element of the set of set a?
elementary-set-theory
elementary-set-theory
edited yesterday
asked yesterday
edmonda7
413
413
add a comment |Â
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
7
down vote
Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
 |Â
show 3 more comments
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
7
down vote
Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
 |Â
show 3 more comments
up vote
7
down vote
Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
 |Â
show 3 more comments
up vote
7
down vote
up vote
7
down vote
Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.
Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.
answered yesterday
Theo Bendit
12.9k1944
12.9k1944
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
 |Â
show 3 more comments
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
1
1
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
– xbh
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
– edmonda7
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
– xbh
yesterday
2
2
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
– Theo Bendit
yesterday
1
1
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
@xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
– Arthur
yesterday
 |Â
show 3 more comments
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