Boolean algebras are structures which behave similar to a power set with complement, intersection and union. Questions regarding Boolean algebras as structures, or regarding functions defined from/to Boolean algebras fit into this tag very nicely. For Boolean logic use the tag propositional logic

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How to prove this tautology using equivalences?

I am trying to prove that the following is a tautology: $(A \implies (B \implies C)) \implies ((A \implies (C \implies D)) \implies (A \implies (B \implies D)))$ To make progress, I thought I'd ...
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1answer
30 views

Proving that a set with a ternary logical connective is functionally incomplete (i.e. inadequate)

I am stucked at trying to prove that the set $\{\lnot ,G\}$ of logical connectives is inadequate where $G$ is a ternary connective that gives $T$ (True) if most of its arguments are $T$. For example: ...
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1answer
18 views

Number of Linear boolean-functions [on hold]

How many linear boolean functions are there, if we have n variable?
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38 views

Translating English to symbolic logic

(Question prompt) The domain of discourse in this problem is the set of students and teachers at a school. Define the following predicates: • E(x, y): x has sent a letter to y. • P(x): x is a ...
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Boolean functions in functionally incomplete boolean operator sets

A set of boolean operators is called functionally complete if and only if any of the $2^{2^n}$ boolean functions in $n$ variables can be represented using a boolean expression that contains operators ...
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5 views

Secondary essential prime implicant

I am having problem understanding what excatly are secondary essential prime implicants. Essential prime implicants(PI) are clearly those which cover an output which no other PI is able to cover but ...
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1answer
36 views

Prove that a boolean function using only $\vee$ and $\wedge$ must attain the value $1$ at least once

Please give me feedback on this Prove that a boolean function constructed only by using $\vee$ and $\wedge$ (without using $\sim$ ) must attain the value $1$ at least once.
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70 views

$\sim p$ ,$\sim\sim\sim\sim\sim p$ , and $\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim p$ . Which of these are equal?

I made an attempt on this question. Please guide me if its wrong. Consider the following boolean fuctions: $\sim p$ ,$\sim\sim\sim\sim\sim p$ , and $\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim\sim ...
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complete set of connectives [closed]

How can I prove that $\{f,XOR\}$ is a complete set of connectives which : f = a'*(b XOR C) (b XOR c = b'c+b c') I try so hard to prove it , but i didn't succeed i need help!! I can get a+b and i ...
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61 views

What's the relationship between continuity property of Lebesgue measure and continuity on a metric space?

This is a topic from Lebesgue measure in $\textit {Carothers' Real Analysis}$: I know how to prove Theorem 16.23. However, I can not figure out why he names this property as continuity? Besides ...
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1answer
17 views

Essential Prime Implicants and Minterm Expressions

I have an exam for a university course shortly, and upon reviewing one of my assignments I have come to realize that I don't understand why I have lost marks/how to do a couple of questions. Hopefully ...
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Boolean Algebra: a+a'b = a+ab = a?

a(a'+b) = aa'+a'b = a'b (aa' = 0 in any case) a+a'b = 1a + a(a'+b) = a(1+a'+b) = a a+ab = a(a+b) = a => a+a'b = a+ab However when I use truth table to compare the result of a+a'b to a+ab when a = ...
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25 views

How many solutions does this boolean equation system has?

How many solutions does this boolean equation system has? $$\left\{ ...
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1answer
23 views

How would one solve this boolean algebraic equation?

During software testing I needed to find at least one solution for this: (a or (b and c)) != ((a or b) and c) Where all variables are boolean. I can (and did) ...
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1answer
5 views

how to simplify (x+y')X(x+z')?

Hi this is for a Discrete Math test I have today. I can barely understand the simplification of boolean expressions. Can anyone show me if the (x+y')X(x+z') can be simplified further, what are the ...
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42 views

Prove that $x+(\overline{x}\cdot\overline{y})=x+\overline{y}$

Prove that $x+(\overline{x}\cdot\overline{y})=x+\overline{y}$ The values of both these boolean functions show that these 2 are equivalent. ...
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1answer
30 views

karnaugh map simplification

I really wonder why my method is wrong. Could you explain step-by-step and why my methods wrong. Drawings includes just one time isn't it enough for simplification ? First boolen expression: $$ F = ...
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1answer
25 views

Boolean Expression Simplification XOR

I have been trying to express XOR in terms of just the '&' and '~' operators. I have managed to get the original XOR definition (~x & y) | (x & ~y) down to ~(x & y) & ~(~x & ...
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1answer
15 views

An effective way to find missing minterms

I've been messing with logic formulas lately and there was one thing that was often causing me headache. I'll describe it briefly. When using Quine-McClausky's algorithm for finding MDNF and MCNF, I ...
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2answers
34 views

Simplifying $(\neg x\land \neg y \land \neg z) \lor (\neg x\land \neg y \land z) \lor (x\land \neg y \land z) \lor ( x\land y \land z)$

I'm looking at this logical formula: $(\neg x\land \neg y \land \neg z) \lor (\neg x\land \neg y \land z) \lor (x\land \neg y \land z) \lor ( x\land y \land z)$ Asked to simplify it as much as ...
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1answer
45 views

Boolean Algebra: Is this equality or inequality?

Consider: $$xy + x'y' + yz = xy + x'y' +x'z$$ Is this equality true? I know I could a truth-table but I prefer doing it algebraically. I think there's something tricky here (Like adding a term, ...
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Boolean Algebra - reducing a function

Let $$f(w,x,y,z) = w'x'y'z' + w'x'yz' + wx'yz'$$ How can you reduce it to: $$x'z'(w' +y)$$ Thanks!
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Boolean algebra proof - I don't know why this is valid!

So this is the answer proof I was given, I'm stumped by the final application of the Idempotent law (where does that 1 come from!?) As I understood it a 0 or 1 can only come from a combination of A ...
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1answer
20 views

A Criterion For a Set To Have all the Atoms of a Boolean Algebra

Let $\Omega$ be any set and let $\mathcal A$ be an algebra of sets in $\Omega$. An element $E\in \mathcal A$ is said to be an atom if there is no non-empty element $A\in \mathcal A$ such that ...
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How many ways are there to sit 4 people from a group of 10 people around a circular table where two sittings are considered

How many ways are there to sit 4 people from a group of 10 people around a circular table where two sittings are considered the same when everyone has the same immediate left and immediate right ...
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1answer
40 views

How many binary bit strings of length 32 are there

How many binary bit strings of length 32 are there? I think I know the answer but I'm not sure...wouldn't it just be $2^5$ ?
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35 views

How to prove an equality in a Lindenbaum-Tarski algebra?

Let $\mathscr{L}'= \mathscr{L}\cup \mathscr{C}$ be an extension of the language $\mathscr{L}$ with a new infinite set of constants $\mathscr{C}$, and $T$ be an $\mathscr{L}$ theory. I wish to show ...
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1answer
21 views

Each Element of an Algebra can be Partitioned into “Atoms”

Let $\Omega$ be any set and let $\mathcal A$ be an algebra of sets in $\Omega$. An element $E\in \mathcal A$ is said to be an atom if there is no non-empty element $A\in \mathcal A$ such that ...
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5answers
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Boolean Simplification of AB + A'+B'

Is there any way to simplify this function? Or is this the simplest equation? : AB + A'+B'
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Question on Boolean Algebra - Atomicity and Completeness

I am trying to solve some Boolean Algebra exercises from the book of Mathematical Logic by Cori and Lascar. I am having some problem in solving a question. Please help me. Thnx in advance. I was ...
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1answer
64 views

What is the difference between Boolean logic and propositional logic?

As far as I can see, they only employ different symbols but they operate in the same way. Am I missing something? I wanted to write "Boolean logic" in the tag box but a message came up saying that if ...
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1answer
22 views

simplifying boolean expression in maxterm

Should I expand the equation to simplify? Π(1,4,5,6). It means $$ F = (A + B + C')(A' + B + C)(A' + B + C')(A' + B' + C) $$ I have expanded and found $$ = ( C' + AC + A'B)(A' + BC + B'C') $$ I haven't ...
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2answers
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simplifying boolean expression in minterm

i am trying to simply the equation and stuck. Sum symbol(2,4,6,7). It means $$ F = A'BC' + AB'C' + ABC' + ABC $$ $$ = A'BC' + AB'C' + AB(C' + C) $$ $$ = A'BC' + AB'C' + AB $$ After the last equation ...
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1answer
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expanding boolean expression as maxterm

$$ F = A + B'C $$ The expression has bothered. I've tried to expand the expression in maxterm, however, I'm stuck on the $B'C $ part. My approach is like this $$ = A + (B'B) + (C'C) + B'C $$ $$ = (A + ...
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What is the algorithm to add 2 binary with boolean operations? [closed]

What is the algorithm to add up 2 binary numbers when the basis is {negation, conjunction, disjunction} in linear time? Also the program needs to be linear as well, meaning there can only be ...
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3 input XOR gate

I am just beginning in computer engineering and need help with a problem. I have to implement a circuit following the boolean equation A XOR B XOR C, however the XOR gates I am using only have two ...
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Probability of boolean function

I have a boolean function $F(x_1,...,x_n)$ given in disjunctive normal form. $x_1,...,x_n$ are independent random boolean variables following Bernoulli distribution, i.e. $x_i = True$ with probability ...
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2answers
69 views

Show that every boolean function with 3 variables can be represented with maximum number of 10 gates

I need to show that every Boolean function with 3 variables can be represented with maximum number of 10 gates, limited to the following: AND(2 ins), OR(2 ins), NOT(1 in). I tried to find Boolean ...
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1answer
28 views

Consensus Theorem: Legal to use redundant terms to find more redundant terms?

When using the Consensus Theorem in Boolean algebra to minimize an expression, is it a legal move to find and add a redundant term to the expression and then use that term to find more redundant terms ...
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Basic Boolean Algebra Multiplication Question

I have the following term $$ t1: \overline {\overline{x1x2\Leftarrow\Rightarrow x1x3}\Leftarrow\Rightarrow x2x3} $$ which I already converted to this: $$ t2: ((x1x2\overline{x1x3} + ...
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3answers
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Boolean Algebra: Simplifying $\;xyz + x'y + xyz'$

Given the following expression: $xyz + x'y + xyz'\,$ where ($'$) means complement, I tried to simplify it by first factoring out a y so I would get $\;y(xz + x' + xz').\,$ At this point, it appears ...
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1answer
16 views

Equivalent form of biconditional

I'm reading How to Prove It: A Structured Approach (Velleman) Second Ed. Doing all the end of chapter exercises for chapter 1 and having trouble on problem 5a which reads Show that $P ...
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24 views

Reference for the fact: elements as union of atoms in a Atomic Boolean lattice [closed]

I need a reference to a book with the following statement: "In a Atomic Boolean Lattice every element is the union of the atoms under lie it". Does not matter if it is presented as a exercise.
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26 views

The proof of that a → b is equivalent to ¬b → ¬a using algebraic identities by ArsDigita

I'm noob practicing with discrete math problems, and not sure if the solution ArsDigita provided for this one is correct or not: Prove that a → b is equivalent to ¬b → ¬a using algebraic identities. ...
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Monotonic operators in classical logic

Which means monotony for a logical operator, and affinity, in propositional calculus affinity..., here on wiki do not quite understand!!
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28 views

Simple Boolean Algebra Question

I have the following term in front of me: $$(AB+AC+\overline BC+B\overline C)*(A+\overline B+C+D)$$ and just need to multiply the whole thing which should result in this: ...
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26 views

Is the algebra of these circuits valid?

I drew these circuits when I was studying Boolean Algebra. Is the algebra of these circuits valid?
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proof that k-maps give the most minimized result?

how can i prove that a k-map for n variables gives the most simplified representation of a Boolean function ? (by simplified i mean we cannot eliminate another variable)
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1answer
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Understanding comparability in a partially ordered sets with Hasse diagrams

I'm doing a section on directed graphs and Hasse diagrams right now on partially ordered sets, and I'm trying to understand what it means for two elements in a Hasse diagram to be comparable. For ...
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1answer
24 views

Convert boolean expression to pos then nor only

I'm trying to convert a + xb + xyz to POS then to nor only. First I got, a'(x' + b')(x' + y' + z') by using the duality rule but then I get confused after that. Thanks.