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A comment on Rice’s Theorem: An interactive tutorial. Parent comment

Re:Rice’s Theorem: An interactive tutorial by wizeman on Sunday November 27, 2022 @06:47PM (#33768202)
Also, I don't quite understand what the program QQ is.

Q is a program that takes one input P.

But then you said "QQ is a program which executes Q with itself as input".

So in the program QQ, the first Q uses the second Q as input, but what does the second Q use as input?

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Re:Rice’s Theorem: An interactive tutorial by vladsotirov on Sunday November 27, 2022 @08:12PM (#33768733)
The second Q needs no input because it is not executed: its source code is used as input for the first Q.
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Re:Rice’s Theorem: An interactive tutorial by wizeman on Sunday November 27, 2022 @08:33PM (#33768846)
> The second Q needs no input because it is not executed: its source code is used as input for the first Q.

But Q is the source code of a program that needs an input.

How would you determine if Q halts or not, if you don't give it an input?

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