Tutors Answer Your Questions about Proofs (FREE)
Question 687765: Hello I am supposed to symbolize English arguments using the schemes and abbreviations provided and then construct proofs to show that the arguments are valid.
This one is:
Either we should stop going places, or we should develop hydrogen-powered cars, or we should go on driving gasoline-powered cars. We should go on driving gasoline-powered cars only if we should destroy the ozone layer. We should not stop going places and we should not destroy the ozone layer. Therefore, we should develop hydrogen-powered cars. (P: We should stop going places; H: We should develop hydrogen-powered cars; G: We should go on driving gasoline powered cars;O: We should destroy the ozone layer)
So far I just tried to construct the abbreviation, but I don't feel like it fits with the forms.
I have:
Pv(HvG)
G<->O
P.o
H
And on top of that I am really not understanding how to formulate proofs for my class. I thought I was grasping it really well up until now. Any help would be appreciated. Walking me through the problem would be amazing.
Click here to see answer by MRperkins(300)   |
Question 694575: I'm having a ton of trouble figuring out this proof for our take-home quiz. We're only supposed to use the first 8 rules of solving propositional logic, which include modus ponens, modus tollens, constructive dilemma, hypothetical syllogism, disjunctive syllogism, simplification, conjunction, and addition. Here's what I have so far:
1. R->S given
2. P->Q given
3.[(PvK) & N]->(K->R) given
4. PvK given
5.N given
6.(PvK) & N 4,5 conj.
7.K->R 6,6 M.P.
8.K->S 1,7 H.S.
...and that's where I get stuck. Any help would be great. I'm trying to reach a conclusion of QvS, which makes me think the last few steps are going to be constructive dilemma but it's really difficult to get there. Thanks!
Click here to see answer by jim_thompson5910(35256) |
Question 697321: there was blind man he his having wife and a dumb friend, once a man kissed his wife while kissing his friend saw that.. now how will dumb person say to blind person that somebody kissed his wife?????????????
Click here to see answer by lynnlo(4176) |
Question 706228: a pipe can fill a tank in 12 hours and another can empty in 24 hours. if both the pipes are used, with the first pipe running for 2 hours and second pipe running for 1 hour, alternatively, starting with the first pipe, then how long will it take to fill the tank
Click here to see answer by josmiceli(19441)  |
Question 732042: Hello,
In my assignment I am required to show why the rule of indirect proof is unnecessary. That is: show that if from a sentence p it is possible to derive q and not q, then there will be a way to derive not p without using indirect proof. The assignment also gives a hint, that the derivation will probably involve Conditional Proof.
Thank you so much for your help.
Click here to see answer by lynnlo(4176) |
Question 732506: For each of the following cases, without using a truth table, write down the condition(s) under which the compound proposition will be true. Explain briefly.
(a) (p v ~q) ^ (q v ~r) ^ (r v ~p)
(b) (p v q v r) ^ (~p v ~q v ~r)
Click here to see answer by solver91311(24713)  |
Question 732703: We have to proof these arguement by using the 17 rules of inference.
1) 1. (z>x) . (x>~z)
2. zvx
3. ~x / A.B
2) 1. Bv(S.N)
2.B>~S
3. S>~N/ BvW
3) 1. (Q.F) v R
2. (QvR) >~P
3. ~A / ~(AvP)
4) 1. A>~A/ ~A
5) 1. A>B
2. C>B/ (AvC)>B
6) 1. S>R/ S>(RvT)
7) 1. ~A>(B>~C)
2. ~D>(~C>A)
3. Dv~A
4. ~D/ ~B
8) 1. (S>B)>(SvK)
2. (Kv~D)>(H>S)
3. ~S.W/ ~H
9) 1. (Z.Y)>X
2. ~O>Z
3. ~Y>O
4. ~O.T/ X
10) 1. F>G
2. ~HvI
3. (GvI)>J
4. ~J/ ~(FvH)
*I am so confused if any one could help, I would greatly appreciate it.
Click here to see answer by lynnlo(4176) |
Question 732911: Determine whether each of the following sentences is truth-functionally true, truth-functionally false or truth-functionally indeterminate by constructing truth table.
( [ ( C ⇒ D ) & ( D ⇒ E ) ] & C ) & ~ E
Click here to see answer by lynnlo(4176) |
Question 732943: 1. (EvF)$(E->L,L->M,D.(D&F(->F)->L |- L&M
2. FvI, F->(-D->N), -D,I->P,P->T,(T&-D)->(B->N),B |- N
3. (A&P)v (-A&-C) |- P v -C
4. B->(FvG),(F->N)&(G->N),B |- M v N
5. D, D->(KvB), K-> -T, B-> -T, -N->T |- N
I am completely lost on this subject and took these out of a study guide and would like to have them solved so I can see how all of them work, then try to build my own and compare to how these were solved to see if I can do them. Please help me.... I will forever be in your debt!!
Thank you,
Jill
Click here to see answer by lynnlo(4176) |
Question 734973: Proving Logical truths:
[~y⊃(~f∨s)]≡[~f∨(y∨s)]
How do I prove this conditional statement using Indirect Proof method(which I tried and ended at 20 lines with the problem still unsolved) or conditional Proof method. I know I need to use the conditional Method but I can't figure out where to begin. I know I need to assume the first part....
[~y⊃(~f∨s)
Not sure where to go next.
Click here to see answer by lynnlo(4176) |
Question 742285: Define a relation R on the set of integers by mRn if and only if 3 divides m - n.
Prove or disprove that R is reflexive.
This is what I have, the problem is i'm not sure where Im supposed to get to.
Assume mRn and let 3 divide m-n, for some integers m and n.
By definition of divides, 3=(m-n)(k), for some integer k.
Click here to see answer by jim_thompson5910(35256) |
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