Informal proof of diagonal lemma
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I am reading this proof of the diagonal lemma
and I do not understand what is happening here. Could you informally explain what is the strategy here? I would appreciate it if you went step by step. I am aware of this informal exposition, but I don't think it explains the proof itself.
logic
asked Nov 19 at 19:33
M. Moe
31
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I am reading this proof of the diagonal lemma
and I do not understand what is happening here. Could you informally explain what is the strategy here? I would appreciate it if you went step by step. I am aware of this informal exposition, but I don't think it explains the proof itself.
logic
asked Nov 19 at 19:33
M. Moe
31
1
Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I am reading this proof of the diagonal lemma
and I do not understand what is happening here. Could you informally explain what is the strategy here? I would appreciate it if you went step by step. I am aware of this informal exposition, but I don't think it explains the proof itself.
logic
asked Nov 19 at 19:33
M. Moe
31
I am reading this proof of the diagonal lemma
and I do not understand what is happening here. Could you informally explain what is the strategy here? I would appreciate it if you went step by step. I am aware of this informal exposition, but I don't think it explains the proof itself.
logic
logic
asked Nov 19 at 19:33
M. Moe
31
asked Nov 19 at 19:33
M. Moe
31
asked Nov 19 at 19:33
M. Moe
31
asked Nov 19 at 19:33
M. Moe
31
asked Nov 19 at 19:33
M. Moe
31
31
1
Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34
add a comment |
1
Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34
1
1
Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34
add a comment |
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You could try §47 of the notes Gödel Without Tears, which is still rather terse buy the notation might be a bit more helpful.
https://www.logicmatters.net/resources/pdfs/gwt/GWT2f.pdf
answered Nov 20 at 0:07
Peter Smith
40.4k339118
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You could try §47 of the notes Gödel Without Tears, which is still rather terse buy the notation might be a bit more helpful.
https://www.logicmatters.net/resources/pdfs/gwt/GWT2f.pdf
answered Nov 20 at 0:07
Peter Smith
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add a comment |
up vote
1
down vote
You could try §47 of the notes Gödel Without Tears, which is still rather terse buy the notation might be a bit more helpful.
https://www.logicmatters.net/resources/pdfs/gwt/GWT2f.pdf
answered Nov 20 at 0:07
Peter Smith
40.4k339118
add a comment |
up vote
1
down vote
up vote
1
down vote
You could try §47 of the notes Gödel Without Tears, which is still rather terse buy the notation might be a bit more helpful.
https://www.logicmatters.net/resources/pdfs/gwt/GWT2f.pdf
answered Nov 20 at 0:07
Peter Smith
40.4k339118
You could try §47 of the notes Gödel Without Tears, which is still rather terse buy the notation might be a bit more helpful.
https://www.logicmatters.net/resources/pdfs/gwt/GWT2f.pdf
answered Nov 20 at 0:07
Peter Smith
40.4k339118
edited Nov 20 at 0:12
answered Nov 20 at 0:07
Peter Smith
40.4k339118
answered Nov 20 at 0:07
Peter Smith
40.4k339118
answered Nov 20 at 0:07
Peter Smith
40.4k339118
40.4k339118
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Could you expand on which part of the proof you don't understand? That would help others explain it. There's not really much of an informal strategy, except "construct the thing the theorem says must exist". The construction is hard to discover - it's the kind of proof that you simply check step by step.
– Carl Mummert
Nov 20 at 0:11
See also the post proving-and-understanding-the-fixed-point-lemma-diagonal-lemma-in-logic
– Mauro ALLEGRANZA
Nov 20 at 7:34