Prposition logic | Computer Science homework help

The following quiz must be completed

 

Question 1

Not yet answered

Marked out of 100

Flag question

Question text

Which of these statements are true, for propositional logic? (In an exam you would have to justify your answers).

Select one or more:

A. If a formula is not satisfiable then it is not valid

B. X is not satisfiable if and only if ¬X is valid

C. If a formula is not valid then it is not satisfiable

D. X is not valid if and only if not X is satisfiable

Question 2

Not yet answered

Marked out of 100

Flag question

Question text

For each propositional formula below, construct a truth table. Which formulas are valid?

Select one or more:

A. (prightarrow p)

B. p

C. (pwedge q)

D. ((prightarrow(qvee r)) leftrightarrow((prightarrow q)vee(prightarrow r)))

E. (prightarrow(qrightarrow p))

Question 3

Not yet answered

Marked out of 100

Flag question

Question text

In each case say if the formula is satisfiable.

Select one or more:

A. neg(prightarrow(qrightarrow p))

B. p

C. neg((prightarrow q)rightarrow p)

D. (pwedge q)

E. (pwedgeneg p)

Question 4

Not yet answered

Marked out of 100

Flag question

Question text

Which of the following sets of connectives are functionally complete for propositional logic?

Select one or more:

A. wedge, vee, neg

B. rightarrow, bot (false)

C. vee, neg

D. wedge, vee

E. rightarrow, wedge

Question 5

Not yet answered

Marked out of 100

Flag question

Question text

Which of the following are propositional formulas, according to the strict definition of propositional formulas?

Select one or more:

A. neg(p)

B. prightarrow q

C. (pwedge q)

D. ((prightarrow q)rightarrow p)

E. (pwedge qwedge r)

Question 6

Not yet answered

Marked out of 100

Flag question

Question text

Consider the following 11 propositional formulas

  1. (prightarrow(qrightarrow p))

  2. (q rightarrow p)

  3. ( neg p vee  q )

  4. (neg p wedge neg q )

  5. (p vee neg p )

  6. (p vee neg q )

  7. ((p veeneg q) wedge (neg p vee q))

  8. (p wedgeneg p)

  9. (p rightarrow  q)

  10. ((p wedge neg q) vee (neg p wedge  q))

  11. (p leftrightarrow  q)

Which of these eleven formulas are equivalent to each other. Choose one from the following:

Select one:

A. 1=5, 2=3, 7=11, 4=10, 6=9

B. None of the other answers are right

C. 1=5, 2=6, 3=9, 7=11

D. 1=5, 2=6, 4=7=10, 3=9

E. None are equivalent

Question 7

Not yet answered

Marked out of 100

Flag question

Question text

Which of the following propositional formulas are in disjunctive normal form?

Select one or more:

A. neg p

B. (p veeneg q)

C. ((p veeneg q) wedge r)

D. ((p wedge q) vee (neg p wedgeneg q))

E. ((neg p wedge q) vee (p wedge neg q))

Question 8

Not yet answered

Marked out of 100

Flag question

Question text

Which of the following statements is true?

Select one or more:

A. There is a DNF formula which is equivalent to all possible propositional formulas.

B. There is no DNF formula equivalent to (p wedgeneg p)

C. For every propositional formula there is a CNF formula equivalent to it.

D. For every propositional formula there is a DNF formula equivalent to it.

Question 9

Not yet answered

Marked out of 100

Flag question

Question text

Let i be the propositional valuation where i(p) = t, i(q) = t, i(r) = f, …

Let v be the truth function that extends i. Which of the formulas below evaluate to true under this valuation v?

Select one or more:

A. (((p leftrightarrow  q) rightarrowneg(p wedgeneg r)) veeneg r )

B. (neg p rightarrow  (q wedgeneg p))

C. (p wedgeneg r)

D. (neg p rightarrow  q)

Question 10

Not yet answered

Marked out of 100

Flag question

Question text

Let L be a first order language with just one predicate, =, and no constants or function symbols. Let An be a sentence that is true in a structure M if and only if M has at least n points in its domain. What is the smallet number of variables required to write such a sentence An?

Select one:

A. 2

B. n

C. n-1

D. 1

E. infinity

Question 11

Not yet answered

Marked out of 100

Flag question

Question text

Let S=({mathbb N}, I) where I(<^2) is the set of all (x, y) where x is strictly less than y, constants 0, 1 denote zero and one respectively.  Which of the following first order formulas are true in the structure S?

Select one or more:

A. forall xexists y <^2(x, y)

B. neg (<^2(0, 1)rightarrow(0=+^2(0, 1)))

C. <^2(1, +^2(1, 0))

D. forall xexists y <^2(y, x)

E. (<^2(1, +^2(0, 0))vee (1=+^2(0, 1)))

Question 12

Not yet answered

Marked out of 100

Flag question

Question text

Let S be the structure ({mathbb N}, I)  where the domain is the set of natural numbers and  I(<) is the set of pairs (x, y) where x is strictly less than y. Using S and the assignments A1 to A5 below, say which of the following are true.

A1:

x -> 7

y -> 14

z -> 9

w -> 5 (all other vars w)

 

A2:

x -> 8

y -> 7

z -> 9

w -> 5 (all other w)

 

A3:

x -> 0

y -> 14

z -> 9

w -> 5 (all other w)

 

A4:

x -> 8

y -> 14

z -> 9

w -> 5 (all other w)

 

A5:

x -> 6

y -> 14

z -> 9

w -> 5 (all other w)

Select one or more:

A. S, A1 |= small exists x <^2(x, 1)

B. S, A1 |= small forall xexists y <^2(x, y)

C. S, A3 |= small <^2(x, 1)

D. S, A2 |= small <^2(x, 1)

E. S, A2 |= small negexists z(<^2(y, z)wedge <^2(z, x))

Question 13

Not yet answered

Marked out of 100

Flag question

Question text

Let L be a first-order language with just = as a predicate and no constants or function symbols. How many variables to you need to express a sentence that is true in a model if and only if the domain has exactly n elements?

Select one:

A. 2

B. n+1

C. n

D. n-1

E. 2n+1

Question 14

Not yet answered

Marked out of 100

Flag question

Question text

In the following formula > means greater than, = means equals, * means times. Which statement below is a good translation of the first order formula?

small forall x[neg(exists yexists z(x=y*zwedge y>1wedge z>1))rightarrowexists w(w>xwedgeneg(exists yexists z(w=y*zwedge y>1wedge z>1)))]

 

Select one:

A. for every composite number there is a prime number

B. for every prime number there is a bigger prime number

C. x and w are prime numbers

D. all numbers bigger than x are prime.

E. for all x, if x is a prime number then w is a prime number.

Question 15

Not yet answered

Marked out of 100

Flag question

Question text

Consider the first order formula:

small (forall x(exists y P^2(x, y)rightarrow R^2(y, x))rightarrow Q^1(x))

Which statements are correct?

Select one or more:

A. The scope of small forall x is small ((exists y P^2(x, y)rightarrowexists x R^2(y, x))rightarrow Q^1(x))

B. the scope of small exists y is small P^2(x, y)

C. small R^2(y, x) is in the scope of small exists x and small exists y, but not in small forall x.

D. there is one free occurence of small x: the small x in small Q^1(x)

E. This is not a well-formed formula.

Question 16

Not yet answered

Marked out of 100

Flag question

Question text

Take a first order language with constants C = {0,1}, predicates P = {R^2} and functions F = {+^2, -^1, times^2}.

Which of the following are terms in this language?

Select one or more:

A. +^2(x, y, 1)

B. times^2(+^2(0, 1), +^2(0, 1))

C. R^2(x, 0)

D. -^1(0, 1)

E. +^2(3, 0)

Question 17

Not yet answered

Marked out of 100

Flag question

Question text

Let S be the structure ({mathbb N}, I)  where I(<) is the set of pairs (x, y) where x is strictly less than y.Which of these first order formulas are valid in S?

Select one or more:

A. exists xforall y(<^2(x, y)vee (x=y))

B. forall yexists x(<^2(x, y)vee (x=y))

C. forall xforall y((<^2(x, y)vee <^2(y, x))vee x=y)

D. forall yexists x <^2(y, x)

E. exists xforall y <^2(y, x)

Question 18

Not yet answered

Marked out of 100

Flag question

Question text

Which of these first order formulas are valid?

Select one or more:

A. (forall xneg R^1(x) rightarrownegexists x R^1(x))

B. (exists xforall y <^2(x, y)rightarrow forall yexists x <^2(x, y))

C. forall xforall y ((<^2(x, y)vee <^2(y, x))vee(x=y))

D. (forall xexists y <^2(x, y) rightarrow exists yforall x <^2(x, y))

Question 19

Flag question

Question text

Predicate Logic. Consider the following assignments.

A1:

x -> 7

y -> 14

z -> 9

w -> 5 (all other vars w)

 

A2:

x -> 8

y -> 7

z -> 9

w -> 5 (all other w)

 

A3:

x -> 0

y -> 14

z -> 9

w -> 5 (all other w)

 

A4:

x -> 8

y -> 14

z -> 9

w -> 5 (all other w)

 

A5:

x -> 6

y -> 14

z -> 9

w -> 5 (all other w)

 

Which statements are correct?

Select one or more:

A. A1 is an x-variant of A3

B. A5 is a z-variant of A5

C. A4 is a z-variant of A5

D. A2 is a y-variant of A4

E. A3 is an x-variant of A5

Question 20

 

Question text

Let S be the structure ({mathbb N}, I)  where I(<) is the set of pairs (x, y) where x is strictly less than y, I(+) is the ordinary addition function, I(0), I(1) are the integers zero, one respectively..Using the structure S  calculate the interpretation of

+2(+2(1,1), +2(0,1))

Answer:

Question 21

Let S be the structure ({mathbb N}, I)  where I(<) is the set of pairs (x, y) where x is strictly less than y. Let A be the assignment where x -> 5 and y -> 8.

Calculate [+ 2(x, y)]S,A

Answer:

 

 

 

 

 

Place your order
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26
The price is based on these factors:
Academic level
Number of pages
Urgency
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more
Open chat
Need help?
Hello,
for enquiries or orders talk to James here