Monday

October 20, 2014

October 20, 2014

Posted by **Elizabeth** on Sunday, November 22, 2009 at 1:54pm.

How do I make sense of this?

"So suppose I have a black box which can decide the halting problem, that is I can give it a program P and the box tells me if P will ever stop.

Using this I can make a program P' that works as follows:

Given a program P ask the box if P will stop.

If P will halt run forever.

If P will run forever, halt.

Last step, give P' as input to itself, if P' will run forever it must halt. "

I don't understand why there is a P' here? And why we have regular P and P'. I'm so confused.

**Answer this Question**

**Related Questions**

Math 157 - I need some help I have to Select one problem from the self-practice ...

problem of the week - Imagine one large cube made of 1000 white centimeter cubes...

Statistics - Suppose 52 of the students in class have a calculator and 14 have a...

computer science - ineed help with c++. i am using code blocks and i have a ...

Physics - Suppose you wish to make a solenoid whose self-inductance is 1.6 mH. ...

physics - Suppose you wish to make a solenoid whose self-inductance is 3.0 mH. ...

Physics - Suppose you wish to make a solenoid whose self-inductance is 1.2 mH. ...

Physics please help! - Suppose you wish to make a solenoid whose self-inductance...

chem plz help! - the rate of a nuclear reaction can be changed by?? i know ...

Physics - Specifically, which of the following best expresses your view: i. Many...