Webpage for Mathematical Logic

Important Question Types:

  1. Checking validity of First Order Logic Statements
  2. Checking validity of Propositional Logic

Recent questions tagged mathematical-logic

2 2 votes
1 1 answer
199
199 views
Given $(P \to (Q \land R)) \land (Q \to R)$, what is the conjunctive normal form?$(\neg P \lor Q)\land(\neg P \lor R)\land(\neg Q \lor R)$ $(P \lor Q)\land(P \lor R)\land...
2 2 votes
4 4 answers
234
234 views
Which of the following statements are true if universe of discourse for all variables consist of all integers?$\forall n \exists m\left(n^{2} < m \right)$$\exists n \exis...
1 1 vote
1 1 answer
127
127 views
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason RAssertion A: If $L$ is regular, then its compliment $L^{\prime}$ is ne...
0 0 votes
1 1 answer
147
147 views
Let C(x,y) mean that student x is enrolled in class y, where the domain for x consists of all students in your school and the domain for y consists of all classes being g...
1 1 vote
3 3 answers
340
340 views
For the statement $$P \rightarrow Q$$Which of the following statements below is/are correct?If the hypothesis is true and the conclusion is false, then the conditional st...
16 16 votes
6 6 answers
2.9k
2.9k views
For two different persons $x$ and $y$, the predicate $M(x, y)$ denotes that $x$ knows $y$. Consider the following statement.There is a person who does not know anyone els...
2 2 votes
1 1 answer
441
441 views
Let $P(x)$ be a predicate.Which of the following statements is/are NOT valid in first-order logic?$\forall x\; P(x) \Rightarrow \exists x\; P(x)$ $\exists x\; P(x) \Right...
1 1 vote
1 1 answer
402
402 views
Which of the following statements is NOT true?(The names of the predicates are intuitive.)$\forall x\ \forall y\ \emph{Classmate(x,y)} \Rightarrow \emph{Classmate(y,x)}$ ...
1 1 vote
1 1 answer
425
425 views
Assume that a Creative $(C)$ person will Succeed $(S)$ if the person is also Disciplined $(D)$, but will not succeed otherwise. Now, consider the following statements:$C ...
2 2 votes
1 1 answer
428
428 views
Sentence $X$ is said to entail Sentence $Y$ if whenever $X$ is TRUE, $Y$ also must hold TRUE.Which of the following statements is/are correct if $X$ entails $Y$?$X \Right...
0 0 votes
0 0 answers
174
174 views
S1:for each x in domain: if P(x) is false: return FALSE return TRUES2:for each x in domain: if P(x) is true: return TRUEreturn FALSEWhich of the fol...
4 4 votes
1 1 answer
662
662 views
Consider the following Boolean expression of a function $F$ :\[F(P, Q)=(\bar{P}+Q) \oplus(\bar{P} Q)\]Which of the following expressions is/are equivalent to $F$ ?$\overl...
3 3 votes
1 1 answer
926
926 views
For two different persons $x$ and $y$, the predicate $M(x,y)$ denotes that $x$ knows $y$.Consider the following statement.$\emph{"There is a person who does not know anyo...
6 6 votes
0 0 answers
536
536 views
Which one of the following options is not a property of Boolean Algebra?Note: $+$ is $\mathrm{OR}$ operation, $. $ is $\mathrm{AND}$ operation, and $'$ is $\mathrm{NOT}$ ...
2 2 votes
1 1 answer
566
566 views
"When it is raining, peacocks dance.''Based only on this sentence, which one of the following options is necessarily true?Peacocks dance only when it is raining. When pea...
1 1 vote
1 1 answer
610
610 views
'When the teacher is in the room, all students stand silently.'If the above statement is true, which one of the following statements is not necessarily true?If any studen...
0 0 votes
0 0 answers
453
453 views
 Exercise 1.1, Question 17Given propositions:$p$: Grizzly bears have been seen in the area$q$: Hiking is safe on the trail$r$: Berries are ripe along the trail(c) If berr...
1 1 vote
1 1 answer
224
224 views
Consider the formula:∀x(P(x)→Q(x)) ∧ ∀x(Q(x)→R(x)) → ∀x(P(x)→R(x))Which is true?A. TautologyB. ContingentC. ContradictionD. Unsatisfiable
0 0 votes
1 1 answer
82
82 views
Consider the $\operatorname{ring} \mathcal{C}(\mathbb{R})$ of continuous real-valued functions on $\mathbb{R}$, with pointwise addition and multiplication. For $A \subset...
0 0 votes
1 1 answer
134
134 views
Prove or disprove each of the statements below.Let $f: \mathbb{R}^{2} \longrightarrow \mathbb{R}$ be a continuous function that takes both positive and negative values. T...
0 0 votes
0 0 answers
65
65 views
Pick the correct statement(s) from below.There exists a maximal ideal $M$ of $\mathbb{Z}[x]$ such that $M \cap \mathbb{Z}=(0)$.If $M$ is a maximal ideal of $\mathbb{Z}[x]...
3 3 votes
0 0 answers
384
384 views
Which of the followings is not a valid property over two fuzzy relations $\tilde{R}$ and $\tilde{S}$ which must be obeyed for performing $\lambda$-cut defuzzifications?$(...
0 0 votes
0 0 answers
234
234 views
Match List I with List II$\begin{array}{|ll|ll|} \hline \textbf{List I} & \textbf{(Operations on Fuzzy Sets)} & \textbf{List II} & \textbf{(Description)} \\ \hline \text{...
0 0 votes
0 0 answers
218
218 views
The mathematical notation to describe logical entailment of a scentence " $\boldsymbol{\alpha}$ entails another sentence $\boldsymbol{\beta}$ " is$\alpha \models \beta$$\...
0 0 votes
0 0 answers
252
252 views
The kind of symbols for basic syntactic elements of first-order logic areConstantDomainPredicateTemporalFunctionChoose the correct answer from the options given below:$\t...
1 1 vote
0 0 answers
206
206 views
Let $\mathrm{L}(x, y)$ be the statement "$x$ loves $y$" where the domain for both $x$ and $y$ consists of all people in the world. Use quantifiers to express "Joy is love...
0 0 votes
2 2 answers
320
320 views
Consider the following if $p$ and $q$ are two statements.$\sim(\mathrm{p} \wedge \mathrm{q}) \equiv \sim \mathrm{p} \vee \sim \mathrm{q}$$\sim(\mathrm{p} \vee \mathrm{q})...
0 0 votes
0 0 answers
181
181 views
If universe of disclosure are all real numbers, then which of the following are true?$\exists x \: \forall y(x+y=y)$$\forall x \: \forall y(((x \geqslant 0) \wedge(y<0)) ...
0 0 votes
1 1 answer
266
266 views
If the universe of disclosure is set of integers, then which of the followings are TRUE ?$\forall \mathrm{n} \exists \mathrm{m} \: \left(\mathrm{n}^{2}<\mathrm{m}\right)$...
0 0 votes
2 2 answers
272
272 views
Given below are two statements:$\text{Statement (I)}$: Truth and falsehood are attributes of individual propositions.$\text{Statement (II)}$: Validity can be attributed t...