need help with discrete mathematics

mrsesyc · 2006-09-17 02:54:51

hello everyone, i'm new to the forum and i was wondering if anyone in here knows about logical equivalences for discrete maths since i have problem with them and im not getting by

Patrick · 2006-09-17 03:01:10

If you want serious help, you might want to be a bit more specific than that

mrsesyc · 2006-09-17 03:09:48

ok here is what i would on (( p imlies q) and (q implies r)) is equivalent to (p implies(q and r) prove this without doing truth tables

Ricky · 2006-09-17 04:25:10

You must first know that:

p⇒q is equivalent to ~p or q

So:

p⇒q and q⇒r is quivalent to (~p or q) and (~q or r)

Try to work it from there, see if you can come up with anything. If you can't, just reply back here and we'll help you.

mrsesyc · 2006-09-17 04:46:45

ok this is what i have
p⇒q and q⇒r
is quivalent to (~p or q) and (~q or r) distribution of and
= ( (~p or q) and ~q) or ((~p or q) and r)
= ((~q and ~p) or (~q or q)) or ((~p and r) or( q and r)
= (((~q and ~p) or F or ((~p and r) or( q and r)
= ~p or (q and r)
= p implies (q and r)

i dont know if this is right but i tired please help me out

Monox D. I-Fly · 2016-12-09 16:09:52

Shouldn't "~q or q" equal T?

Math Is Fun Forum

#1 2006-09-17 02:54:51

need help with discrete mathematics

#2 2006-09-17 03:01:10

Re: need help with discrete mathematics

#3 2006-09-17 03:09:48

Re: need help with discrete mathematics

#4 2006-09-17 04:25:10

Re: need help with discrete mathematics

#5 2006-09-17 04:46:45

Re: need help with discrete mathematics

#6 2016-12-09 16:09:52

Re: need help with discrete mathematics

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