Questions tagged [boolean-algebra]

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Representing binary functions with a finite gate set without exponential blow-up?

It is pretty well taught that any binary function can be represented using CNF. But conversion to CNF can take an exponential number of gates. The truth table is exponentially sized relative to the ...
Andrew Baker's user avatar
0 votes
2 answers
58 views

Polynomial representations of Boolean functions

The AND boolean function $AND(x)$ can be represented using the polynomial $P(x) = x_1x_2\cdots x_n$. I have a few questions: Is there a similar polynomial for the PARITY boolean function? Is there a ...
meeeeee's user avatar
1 vote
0 answers
20 views

Equivalent-symmetric (E-symmetric) variables check for Boolean functions

In [1], it states that checking $f(..., x_i, ..., \bar{x}_j, ...) = f(..., \bar{x}_j, ..., x_i, ...)$ (variables $x_i$ and $x_j$ are E-symmetric) is equivalent to checking $f_{x_ix_j} = f_{\bar{x}_i\...
Drzw's user avatar
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Complexity Class of the Problem: Existence of Unsatisfying Interpretations in Boolean Formulas

What is the complexity class of the problem if there exist two different interpretations that do not satisfy a given Boolean formula? I believe the problem of existence of an interpretation that does ...
Lupital's user avatar
0 votes
0 answers
23 views

SOP Boolean expression of state variable and output of a Moore FSM

Disclaimer: I'm studying for an exam, but I don't have to hand in anything. I have the state transition diagram of the FSM and its states encoding: I want to find the sum-of-products (SOP) Boolean ...
Angelo's user avatar
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1 vote
1 answer
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Why do simple Logical Gates have an Irrational amount of Bits?

Suppose $2$ bits are used to encode a message, A and B. If you know $A$ is $1$, you have one bit of information. If you know $A\land B$ is $1$, you have two bits of information. If you know $A\land B$...
G S's user avatar
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1 vote
1 answer
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Why is conjunctive normal form (CNF) "better" for SAT than disjunctive normal form (DNF)?

When hand-manipulating algebra DNF (sum of products) is easier than CNF (product of sums). Possibly because factoring is more difficult than expanding. So why is it the opposite for computational ...
Stand with Gaza's user avatar
-3 votes
2 answers
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!(ab)*(!a+b)(!b+b)=!a Boolean Algebra

How can I prove that !(ab)(!a+b)(!b+b)=!a* in boolean algebra? This is an exercise from a past paper of my teacher but I can't really find the way to the answer. I would appreciate some help.
user160560's user avatar
0 votes
1 answer
44 views

How to solve boolean SAT with equality constraints

Say I have boolean formula in form of a CNF(x1,x2,...) with $x_i$ being boolean variables. Testing the satisfiability of the CNF is the SAT problem, i.e. determine ...
Andreas H.'s user avatar
5 votes
5 answers
974 views

Prove HAKMEM Item 23: connection between arithmetic operations and bitwise operations on integers

Prove that for $A, B \in \mathbb{Z}$, $A + B = (A \operatorname{\&} B) + (A \mid B) = (A \oplus B) + 2(A \operatorname{\&} B)$ where $\&$ is bitwise AND, $|$ is bitwise OR and $\oplus$ is ...
Ntwali B.'s user avatar
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Is this a valid method to merge clauses in CNF formulas?

Assume $$C_1 = (x_1 \lor x_2 \lor \lnot x_3)\hspace{0.2cm} C_2 = (x_4 \lor x_5 \lor x_3) \hspace{0.2cm} C_3 = (x_3 \lor x_5 \lor x_6)$$ Let $$ \phi_1 = C_1 \land C_2 \land C_3$$ and $$ \phi_2 = (x_1 \...
C Marius's user avatar
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Is this language PSPACE complete

Prove $PSPACE$-completeness of the language $READALLEXACT$ = $\{$$(M, x, 1^ s , t)$ | $A$ deterministic Turing machine $M$ on input $x$ reads all bits of the input in exactly $t$ steps and using no ...
Vahan's user avatar
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1 answer
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Boolean Integer Linear Optimization/Programming

Trying to solve an ILP optimization problem with a number of potential boolean variables and then express constraints on these variables based on those boolean results. Let's say I am doing 5 coin ...
B.D.'s user avatar
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1 answer
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7 segment decoder Combinational Logic Circuits using Logic Gates

How can a 7 segment decoder operation be implemented using boolean NOR gate ONLY? Question: Here's my truth table and k-map: Normal circuit diagram:
Colin Newmann's user avatar
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2 answers
121 views

Two's complement using logic gates

How can a 4-bit two's complement operation be implemented using boolean NOR gate? I search lots of 4-bit two's complement videos and articals, but most of them are using XOR gate.
Colin Newmann's user avatar
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0 answers
25 views

Reed-Muller Form

I'm having trouble with the Reed-Muller Form, I'm using this notation to make it easier: + = or, * = and, ^ = xor. This is the given expression (a + !b) * (b + !c). a + !b = a + (b ^ 1) = a ^ b ^ 1 ^ ...
Tomas82's user avatar
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1 answer
20 views

influence of neighourhood points

Im trying to understand the following question. Suppose $h,f:\{-1,1\}^n\rightarrow \{-1,1\}$ satisfy $\sum_x h(x)f(x)\leq 0.5$, then one can rewrite this as $\textsf{Pr}_x [h(x)=f(x)]\leq 3/4$. Can we ...
wwjohnsmith's user avatar
1 vote
0 answers
76 views

Method for simplifying complex logic tables

Not sure if this is the right StackExchange site, but back in college (20 years ago) I took a Digital Systems Design class where we learned how to reverse engineer a boolean function to meet the ...
hotmeatballsoup's user avatar
0 votes
2 answers
89 views

Boolean Logic when one component switches from 0 to 1

I recently was constructing boolean logic for all sorts of examples from Morris Mano's "Digital Logic and Circuit Design". I noticed that it is possible to construct a boolean logic wrt the ...
P. Patil's user avatar
0 votes
1 answer
55 views

Is there a notation for boolean algebra complexity?

To represent complexity of an algorithm, Computer Scientist is used to using big-O notation. How about complexity of boolean algebra? Boolean algebra is commonly used in digital circuit design with ...
Muhammad Ikhwan Perwira's user avatar
2 votes
1 answer
1k views

Why can't 3-SAT be solved efficiently if you convert all clauses (x ∨ y ∨ z) into (u ∨ z) by introducing a variable?

Let $a_i$, $b_i$, etc., be a literal, i.e., a variable or the negation of a variable. 3-SAT concerns formulas in CNF form: $(a_1 \vee a_2 \vee a_3) \wedge \dots \wedge (b_1 \vee b_2 \vee b_3)$ (3-CNF)....
Daniel Donnelly's user avatar
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0 answers
95 views

Time complexity of negating a CNF formula

Suppose i have a CNF formula. If i negate the CNF formula, then i obtain DNF formula. However, i can't find anywhere on internet that mention the time complexity. What is the time complexity of ...
LLL's user avatar
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1 vote
2 answers
186 views

Combinational logic check if bits is prime

I wonder if there's Digital Logic Circuit (using combinatorial logic gates) that check if number is prime or not. For example given input fixed 8-bit that will produce 1-bit output. 00000101 will ...
Muhammad Ikhwan Perwira's user avatar
1 vote
1 answer
59 views

How many different boolean functions exist up to permutation of its $n$ variables

i am relatively new here, so if this was asked before, feel free to redirect me. I am searching for an answer in form of a (iterative or recursive) Formula or even better, an algorithm to list them ...
vreithinger's user avatar
1 vote
1 answer
43 views

Why do we use {+1, -1} in place of {0, 1} for the Fourier analysis of boolean functions?

I want to know what will change if we keep on using {0,1} for our Fourier analysis of boolean functions? What are the things, which can not be performed with {0,1} and can be done with {+1, -1}?
CST's user avatar
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1 vote
0 answers
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Fourier Dimension of Boolean functions

I was recently reading about Fourier dimension of Boolean functions. What I understand is that if we take the Fourier expansion of $f: \{\pm1\}^n \to \{\pm1\}$ and consider the monomials with non zero ...
kleinbottle's user avatar
1 vote
2 answers
230 views

Clarification regarding linear boolean functions!

I am a little confused when it comes to linear boolean functions. According to this post: What is a simple way of explaining what a linear boolean function means in boolean algebra and relating it to ...
Reppiz's user avatar
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1 vote
1 answer
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How to come up with combination a short-circuit evaluation table?

(a || b) || (c && d)) Given the above, how do I derive the table below: a b c d output T - - - TRUE F T - - TRUE F F T T TRUE F F T F FALSE F F F - FALSE I'm told that this is short ...
Iva l's user avatar
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1 vote
1 answer
59 views

Influence of a variable in composition of Boolean functions

Suppose $f$ and $g$ are Boolean functions without a constant term, and where every variable has the same influence. How to show every variable will have the same influence in $f \circ g$? To me it ...
kleinbottle's user avatar
2 votes
1 answer
63 views

Is $f(X)f^d(X) = 0$ for a Boolean function $f$?

I'm currently trying to understand a step in the proof for in the Crama and Hammer book on Boolean Functions. The proof is Proposition 4.12, which claims that the self-dualization of Boolean $f$ is ...
Berk U.'s user avatar
  • 429
1 vote
1 answer
54 views

Is [F(a, b, c) = a' + b] functionally or logically complete?

I'm having a problem determining whether [F(a, b, c) = a' + b] is functionally(logically) complete or not. I would really appreciate it if you could help me. P.S: I can't have 1 or 0 as input.
Reza Masoumi's user avatar
0 votes
1 answer
39 views

Can element occur in a CNF formula?

For example, is $(X \vee 1)$ a valid formula in conjunctive normal form (CNF)? If yes, then I would have to consider such formulas when trying to prove a statement about all CNF formulas.
LLL's user avatar
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1 vote
0 answers
30 views

Is there an algorithm for generating non comparable boolean vectors?

First some context: A Boolean Network of $n$ components is a function $f$ from the set $\{0,1\}^n$ (set of vectors of $n$ components whose values are 0 or 1) to itself. The dynamical behavior of a ...
Raúl Astete's user avatar
2 votes
1 answer
25 views

sum of Boolean characters larger degree

I was curious if someone knew the answer/reference for the following. So it is well-known that if $S\in \{0,1\}^n$, then $$ \frac{1}{2^n}\sum_{x\in \{0,1\}^n} (-1)^{\langle S, x\rangle}=1 $$ if and ...
postasguest's user avatar
0 votes
0 answers
33 views

Is there an efficient way to generate a pseudo-boolean function from a linear constraint?

I would like to define a pseudo-boolean function $f$ such that $f(x) = 0$ for all logically valid combinations of $x\in{0,1}$ and $f(x) > 0$ for all logically invalid combinations of $x\in{0,1}$. ...
JoeBass's user avatar
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0 answers
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graph representation of a Boolean function

I'm trying to classify a certain family of Boolean functions, and need to represent the function as a graph. Is there any well-known graph representation for a Boolean function that captures the ...
kleinbottle's user avatar
3 votes
1 answer
69 views

Stalmarck's method: x ≡ x → z, does z have to be true?

I have been researching Ståmarck's method 1. In the paper cited here, some rules are given. Rules are made of triplets (x, y, z) such that: y $\to$ z $\equiv$ x where x, y and z are booleans which ...
Leop's user avatar
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1 vote
1 answer
45 views

Is there a known relationship between Kolmogorov Complexity of a binary string and the logic optimization of the corresponding Boolean function?

I haven't thought about how to go about proving it or finding a counterexample (I probably don't have the right background), but it seems intuitive to me that, given some representation of a Boolean ...
user023049's user avatar
-1 votes
1 answer
31 views

Can anyone solve this? Is the answer 4 or 7. I'm confused

I'm trying to solve this but I'm confused with different answers. I'm getting 4 but the answer written is 7. Please guide me.
user9544852's user avatar
1 vote
0 answers
43 views

Efficient bit-level implementation of Boolean polynomials with few variables

A Boolean polynomial in $n$ variables $x_1, \dots, x_n$ is an expression of the form $$\sum_{\mathbf{s} \in \{0,1\}^n} c_{\mathbf{s}} x_1^{s_1} \cdots x_n^{s_n}, \quad \text{ where } c_s \in \{0,1\} .$...
BubbleZ's user avatar
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0 votes
1 answer
183 views

What boolean algebra simplification is applied in this Shannon's expansion?

Found this question about Shannon's expansion. While I am trying to follow its logic, found one super convenience simplification used. Can we do this in general while dealing with boolean algebra? or ...
Maxfield's user avatar
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0 votes
1 answer
77 views

Boolean formula for graph 3COL

For a given undirected graph $G=(V,E)$ I'm trying to construct a boolean polynomially computable formula $\varphi$ with the following property: $\varphi$ is satisfiable $\iff$ vertices of $G$ can be ...
Andy's user avatar
  • 115
2 votes
3 answers
1k views

Why is SAT based on the CNF?

I have been reading up on Boolean logic and, specifically, the Boolean satisfiability problem. I have seen several people mention that the expression must be converted to conjunctive normal form (CNF) ...
user3670473's user avatar
1 vote
1 answer
142 views

Sorting by boolean algebra (hardware) instead of algorithm (software)

Consider there's an 5 elements list that foreach element are 2-bits. Forexample [01,00,10,00,11], if the list is sorted, we hope the output like this [00,00,01,10,11] Maybe that case seems complicated,...
Muhammad Ikhwan Perwira's user avatar
0 votes
0 answers
51 views

Functions expressible in conjunctive normal form, but with XOR replacing OR

What are all the functions $f:\{0,1\}^n\rightarrow\{0,1\}$ that can be expressed as a product of affine Boolean functions? For example, if $x_1,x_2,x_3\in\{0,1\}$ then $x_1x_2x_3\oplus x_2x_3 \oplus ...
user143394's user avatar
-1 votes
1 answer
587 views

Four Queens Problem to a Conjunctive Normal Form

Given a chessboard with 4 rows and 4 columns (4x4) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Assign a Boolean variable to each cell of the board as below (1, 2, 3, etc. are variable names) If a ...
Lee's user avatar
  • 1
4 votes
2 answers
72 views

Compact representation for quantified boolean formula

I got black-box (too big to analyze) boolean formula f(...) with 3 sets of input arguments: $x_1... x_i, y_1... y_j, z_1... z_k$. And I want to find such values for x-arguments that for every y-...
Alexey Kholodkov's user avatar
3 votes
1 answer
328 views

What are the limits of Boolean Algebra?

Any decision problem algorithm can be represented as a boolean expression. The rules of boolean algebra (De Morgan's law, distributivity, etc.) can be used to manipulate and simplify that expression, ...
Joey Peluka's user avatar
1 vote
1 answer
69 views

Definition and use of a Boolean equation system

According to google, a system of boolean equations is defined as follows Essentially, a Boolean equation system is an ordered sequence of fixed point equations over Boolean variables, with associated ...
Albert Hendriks's user avatar
0 votes
0 answers
14 views

Minimization of an expression through K-map, in which there are more chances of errors and with Quine-McCluskey Method there are less chance of errors

Minimization of any expression of 4 variables through K-map, in which there are more chances of errors (like error in grouping) and the same expression with Quine-McCluskey Method there are less ...
Saad Ahmad's user avatar

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