Discrete Mathematics again

In summary, according to the tables of logical equivalences and implications, the given hypotheses (neg [r] -> s), (p -> q), and (neg [q] V neg ) imply (p -> r).
  • #1
mamma_mia66
52
0
:confused: Construct a formal proof of the theorem:

If (p-> q), (neg [r] -> s), and (neg [q] V neg , then (p-> r).

[refer to table of logical equivalences (p62) and the table of logical implication (p62)]The tables are in the textbook Kenneth Ross, 5th edition, Discrete Math's.

First I have to construct the proof line: I am gessing that the hypotheses are like this, but am not sure for their order:
(neg [r] -> s) /\ (p -> q) /\ (neg [q] V neg ) => (p -> r)

Then I need to make the "formal proof of it" using the tables.

Please someone help me with any sugestion how to keep going with this problem.
Thank you:
 
Physics news on Phys.org
  • #2
) Proof: 1. (neg [r] -> s) /\ (p -> q) /\ (neg [q] V neg ) [Given]2. (neg [r] -> s) [Conjunction Elimination from 1]3. (p -> q) [Conjunction Elimination from 1]4. (neg [q] V neg ) [Conjunction Elimination from 1]5. (neg [q] -> neg ) [Implication Equivalence from Table of Logical Equivalences] 6. (neg [q] -> neg ) /\ (p -> q) [Conjunction Introduction from 3, 5] 7. (neg [q] -> (neg /\ (p -> q))) [Implication Equivalence from Table of Logical Equivalences] 8. (neg /\ (p -> q)) -> (p -> r) [Implication Introduction from 2, 7] 9. (p -> r) [Implication Elimination from 8] Therefore, (p -> r) by Modus Ponens.
 

1. What is discrete mathematics and why is it important?

Discrete mathematics is a branch of mathematics that deals with countable, distinct, and finite objects. It is important because it provides the foundational concepts and tools for many fields such as computer science, cryptography, and operations research.

2. What are the main topics covered in discrete mathematics?

The main topics covered in discrete mathematics include set theory, logic, combinatorics, graph theory, and algorithms. These topics are essential in solving problems related to discrete objects and structures.

3. Is discrete mathematics difficult to learn?

The difficulty level of learning discrete mathematics varies from person to person. Some may find it challenging, while others may find it relatively easy. It requires a strong foundation in algebra and critical thinking skills, but with practice and dedication, it can be mastered.

4. How is discrete mathematics applied in real life?

Discrete mathematics has numerous applications in real life, such as in computer science for designing efficient algorithms, in cryptography for secure communication, and in operations research for optimizing decision-making processes. It is also used in fields like economics, biology, and engineering.

5. Can discrete mathematics be used for problem-solving?

Yes, discrete mathematics is an essential tool for problem-solving. Its concepts and techniques can be applied to various real-world problems, making it a valuable skill for scientists, engineers, and mathematicians. It helps in breaking down complex problems into smaller, manageable parts and finding efficient solutions.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
910
  • Set Theory, Logic, Probability, Statistics
Replies
6
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
11K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
16
Views
1K
  • Calculus and Beyond Homework Help
Replies
12
Views
3K
  • Set Theory, Logic, Probability, Statistics
Replies
4
Views
872
Back
Top