# Can you check to see if i did Arguments w/ quantified statements right? Tollens/Ponen

1. Sep 19, 2006

### mr_coffee

Hello everyone! its me!

I'm pretty sure I did these right but I need to make sure, the class average on the hws have been 70s, so i wonder what i got

Directions:
Some of the arguments in 7-18 are valid by universla modus ponens or universal modus tollens; others are invaldi and exhibit the converse or the inverse error State which are valid and which are invalid. Justify your answers.

#14.

If a complication of a computer porgram produces error messages, then the program is not correct.

Compliation of this program does not produce error messages.

.:. This program is correct.

I said P(x) = compliation of a computer program produces error messages
Q(x) = the program is not correct.

So,
$$\forall$$, if P(x) then Q(x)
~P(x)
.:. ~Q(x)

invalid, inverse error.

#17. If an infintie series converges, then its temrs go to 0.

The terms of the infinite series n/(n+1) do not go to 0.

.:. THe infine series n/(n+1) does not converge.

So i wrote:

$$\forall$$ x, if P(x) then Q(x)
~Q(x)
.:. ~P(x)

Valid, Universal modus Tollens.

Thanks!