Consider the first order predicate formula φ:

∀x[(∀z z|x ⇒ ((z = x) ∨ (z = 1))) ⇒ ∃w (w > x) ∧ (∀z z|w ⇒ ((w = z) ∨ (z = 1)))]

Here 'a|b' denotes that 'a divides b', where a and b are integers. Consider the following sets:

S1.  {1, 2, 3, ..., 100}
S2.  Set of all positive integers
S3. Set of all integers

Which of the above sets satisfy φ?

Which one of the following well-formed formulae in predicate calculus is NOT valid?

Which one of the following well formed formulae is a tautology?

What is the correct translation of the following statement into mathematical logic?

“Some real numbers are rational”

Consider the following logical inferences.

I1: If it rains then the cricket match will not be played.
The cricket match was played.
Inference: There was no rain.
I2: If it rains then the cricket match will not be played.
It did not rain.
Inference: The cricket match was played.

Which of the following is TRUE?

Which one of the following options is CORRECT given three positive integers x,y and z, and a predicate

Suppose the predicate F(x, y, t) is used to represent the statement that person x can fool person y at time t. Which one of the statements below expresses best the meaning of the formula ∀x∃y∃t(¬F(x,y,t))?

The binary operation □ is defined as follows

Which one of the following is equivalent to P ∨ Q ?

Consider the following well-formed formulae:

I. ¬∀x(P(x))
II. ¬∃(P(x))
III. ¬∃(¬P(x))
IV. ∃x(¬(P(x))

Which of the above are equivalent?

P and Q are two propositions. Which of the following logical expressions are equivalent?

I. P∨∼Q
II. ∼(∼P∧Q)
III. (P∧Q)∨(P∧∼Q)∨(∼P∧∼Q)
IV. (P∧Q)∨(P∧∼Q)∨(∼P∧Q)

Which one of the first order predicate calculus statements given below correctly express the following English statement?

     Tigers and lions attack if they are hungry or threatened.

Which one of the following is the most appropriate logical formula to represent the statement?

      “Gold and silver ornaments are precious”.

The following notations are used:

  
       G(x): x is a gold ornament
       S(x): x is a silver ornament
       P(x): x is precious

Let fsa and pda be two predicates such that fsa(x) means x is a finite state automaton, and pda(y) means that y is a pushdown automaton. Let equivalent be another predicate such that equivalent (a, b) means a and b are equivalent. Which of the following first order logic statements represents the following:

Each finite state automaton has an equivalent pushdown automaton

Let Graph(x) be a predicate which denotes that x is a graph. Let Connected(x) be a predicate which denotes that x is connected. Which of the following first order logic sentences DOES NOT represent the statement: “Not every graph is connected”?

Consider the following propositional statements:

P1 : ((A ∧ B) → C)) ≡ ((A → C) ∧ (B → C))
P2 : ((A ∨ B) → C)) ≡ ((A → C) ∨ (B → C))

Which one of the following is true?

Let P, Q and R be three atomic prepositional assertions. Let X denote (P ∨ Q) → R and Y denote (P → R) ∨ (Q → R). Which one of the following is a tautology?

What is the first order predicate calculus statement equivalent to the following?

   Every teacher is liked by some student  

Identify the correct translation into logical notation of the following assertion.

      "Some boys in the class are taller than all the girls"  

Note: taller(x,y) is true if x is taller than y.

The following propositional statement is (P → (Q v R)) → ((P v Q) → R)

Which of the following is a valid first order formula? (Here α and β are first order formulae with x as their only free variable)

The following resolution rule is used in logic programming.

Derive clause (P ∨ Q) from clauses (P ∨ R), (Q ∨ ¬R) 

Which of the following statements related to this rule is FALSE?

“If X then Y unless Z” is represented by which of the following formulas in prepositional logic? (“¬“, is negation, “∧” is conjunction, and “→” is implication)

Consider the following formula a and its two interpretations I₁ and I₂

α: (∀x)[Px ⇔ (∀y)[Qxy ⇔ ¬Qyy]] ⇒ (∀x)[¬Px]
I1: Domain: the set of natural numbers
    Px ≡ 'x is a prime number'
    Qxy ≡ 'y divides x'
I2: same as I1 except that Px = 'x is a composite number'.

Which of the following statements is true?

Consider two well-formed formulas in prepositional logic

   F1: P ⇒ ¬P          F2: (P⇒¬P)∨(¬P⇒P)  

Which of the following statements is correct?

Let a, b, c, d be propositions. Assume that the equivalence a ↔ (b ∨ -b) and b ↔ c hold. Then the truth-value of the formula (a ∧ b) → (a ∧ c) ∨ d is always

(a) Show that the formula [(~p ∨ q) ⇒ (q ⇒ p)] is not a tautology.
(b) Let A be a tautology and B be any other formula. Prove that (A ∨ B) is a tautology.

What is the converse of the following assertion?

  I stay only if you go. 

Which of the following propositions is a tautology?

Which of the following is false? Read ∧ as AND, ∨ as OR, ~ as NOT, → as one way implication and ↔ as two way implication.

Which one of the following predicate formulae is NOT logically valid?
Note that W is a predicate formula without any free occurrence of x.

Obtain the principal (canonical) conjunctive normal form of the propositional formula

  (p ∧ q) V (¬q ∧ r) 

Where ‘∧’ is logical and, ‘v’ is inclusive or and ¬ is negation.

(a) Let * be a Boolean operation defined as
If C = A * B then evaluate and fill in the blanks:
(i) A * A = _______
(ii) C * A = _______
(b) Solve the following boolean equations for the values of A, B and C:

Show that proposition C is a logical consequence of the formula

     A ∧ (A →(B ∨ C)) ∧ (B → ~A)  

Using truth tables.

(a) Uses Modus ponens (A, A →|= B) or resolution to show that the following set is inconsistent:

 (1) Q(x) → P(x)V ~ R(a)
 (2) R(a) ~ Q(a)
 (3) Q(a)
 (4) ~ P(y) 

Where x and y are universally quantified variables, a is a constant and P, Q, R are monadic predicates.

(b) Let S be the set of all integers and let n > 1 be a fixed integer. Define for a, b ∈ S, a R biff a-b is a multiple of n. Show that R is an equivalence relation and finds its equivalence classes for n = 5.

Which of the following well-formed formulas are equivalent?