Questions tagged [boolean-ring]
Use this tag for questions related to Boolean rings such as the ring of integers modulo $2$ $\mathbb Z/2\mathbb Z$.
64
questions
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The Boolean lattice of a Boolean ring
I am proving that a Boolean Ring is also a Boolean Lattice.
I defined $\leq$ as $x\leq y$ when $xy=x$. The supremum is $a+b+ab$, and infimum is $ab$. The Max element is $1$, Min is $0$.
I proved that $...
2
votes
0
answers
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Proof verification: Classical Propositional Logic is Post-Complete
Proof verification: classical propositional logic is Post-complete.
I'm trying to prove the Post-completeness of classical propositional logic. In order to do this, I will be proving a theorem about ...
0
votes
2
answers
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Is the Boolean Algebra on two elements {0,1} a ring, field, or both?
I am aware of the difference between field and ring, and I have also read other posts on this site posing similar questions on Boolean Algebra but have been unsatisfied with the focus of the questions ...
1
vote
0
answers
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Star-autonomous categories are categorifications of Boolean algebras?
1. Question
The n-Lab article on the Chu-construction says:
"Armed with just this much knowledge, and knowledge of how star-autonomous categories behave (as categorified versions of Boolean ...
1
vote
2
answers
265
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Prime ideal $\implies$ maximal in a Boolean ring
I want to show that a prime ideal in a non-unital Boolean ring $B$ is maximal ideal.
If the ring contains unity then it is easy. As Boolean rings are commutative, for a prime ideal $P$ the ring $B/P$ ...
0
votes
1
answer
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The Boolean ring $\mathscr{P}(\Bbb N)$ has an ideal $\mathscr{P}(\Bbb N_+)$. Find the elements of $\mathscr{P}(\Bbb N)/\mathscr{P}(\Bbb N_+)$.
Denote $\Bbb N_+ = \Bbb N \setminus\{0\}$. The Boolean ring $\mathscr{P}(\Bbb N)$ has an ideal $\mathscr{P}(\Bbb N_+)$. Find the elements of $\mathscr{P}(\Bbb N)/\mathscr{P}(\Bbb N_+)$ and compute the ...
0
votes
1
answer
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Are Boolean rings integral domains? [duplicate]
Are Boolean rings integral domains?
My assumption was no. The "product" in Boolean rings is the intersection $\cap$ of two sets from $\mathscr{P}(X)$. If Boolean rings we're integral ...
0
votes
0
answers
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Ring with every element idempotent
I am having query in this MCQ.
Let $R$ be a ring such that every element is idempotent then
(a) Every prime ideal is maximal ideal.
(b) Every maximal ideal is prime ideal
(c) if $|R|> 2$ implies $...
0
votes
2
answers
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Proving from De Morgan's laws
I was proving:
$J.K'.L+J.K.L'+JKL=J.(L+K)$
I have done the following:
From LHS:
$J.K'.L+J.K.L'+JKL$
$=J.(K'.L+K.L'+K.L)$
$=J.(K'.L+K.(L'+L))$
Since $L'+L=1:$
$=J.(K'L+K)$
[' is complement]
Now I'm ...
1
vote
0
answers
34
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A question concerning supremum in a Boolean ring
In a Boolean $\sigma$-ring, is it true that for every sequence {$x_n$} and y, we have $supx_n\cdot y = sup(x_n\cdot y)$ ?
Background:
I was reading 'Measure Theory' written by Paul R.Halmos (in the ...
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1
answer
82
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Number of truth outputs of a Boolean function
Disjunctive Normal Form (DNF) A Boolean function $f$ of $n$ variables is said to be in a DNF if it is a disjunction of conjunction in $n$ variables. That is, each conjunction includes all the ...
1
vote
1
answer
220
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Number of terms in a DNF equals the number of truth outputs
In a Boolean function $f$, it seems that the number of terms in a Disjunctive Normal Form (DNF) is equal to the number of truth outputs of $f$. For example,
If $f=A+B$, then clearly, $f$ has $2^2-1=3$ ...
2
votes
1
answer
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A property of Boolean algebra
In a Boolean algebra $\mathcal B$, we know that
$$x+\bar{x}y=x+y\text{ for all } x, y\in \mathcal B.$$
By following the above identity, we can also write
$$xy+\bar{x}yz=xy+yz.$$
Can we write
$$\bar{y}...
0
votes
1
answer
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commutative ring to boolean algebra
Let X be a set. We know that $(P(X),\triangle, \cap )$ is a commutative ring with the zero-element $ \emptyset $ and the one-element $X$. $P(X)$ is the power set, $\triangle$ the symmetrical ...
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0
answers
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Define an isomorphism between finite boolean ring and $\mathbb{Z}_2\times \cdots\times \mathbb{Z}_2$
I'm trying to prove any finite boolean ring $R$ is isomorphic to $\mathbb{Z}_2\times\cdots\times\mathbb{Z}_2$. I know this question is already on this site, but the proofs I saw used the ring's ...
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votes
1
answer
101
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Is Zero ring a Boolean ring?
I have a simple doubt. Is zero ring a Boolean ring? ( We do have $0 ^2 =0$ ). Or do we assume a Boolean ring to be non-zero?. The doubt came in my mind while showing that in a Boolean ring every prime ...
0
votes
1
answer
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What is the algebraic structure of all the quadtrees under these operations?
I was implementing a quadtree in a programming language, and I realized I could define operations such as negation $\bar{x}$, reunion $a\cup b$ and intersection $a \cap b$ on these objects.
These ...
2
votes
2
answers
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Identify $S = 0$ for any set $S$ and form a non-boolean ring out of $\Delta$ on sets?
Let $S$ be a set and define for each $A \subset S$ the negative of $A$ to be $-A = S \setminus A$. So that $A + S\setminus A = S$. Thus we identify $0 = S$. The $+$ operation is still $\Delta$ so ...
0
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1
answer
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Show that atom of Boolean algebra B inside B' is also the atom of B' where B' is subalgebra of B. [closed]
Let B := (B, ≤, ∨, ∧,
c
, 0, 1) be a Boolean algebra and B'
:= (B'
, ≤, ∨, ∧,
c
, 0, 1) be
a Boolean subalgebra of B. Show that an element of B0
that is an atom of B must also
be an atom of B'
. ...
0
votes
1
answer
31
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What is the motivation behind defining $[\alpha] + [\beta] = [(\alpha \land \lnot \beta) \lor (\lnot \alpha \land \beta)]$?
Consider $\mathcal{F}$ to be the set of all well-formed formulae (wffs), and $\mathcal{F}/\equiv$ denotes the set of equivalence classes under the equivalence relation induced by $\equiv$ (logical ...
0
votes
1
answer
159
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Proof verification: prime ideals in Boolean rings
This question have been answered many times but I didn't find a similar proof, I submit it here for verification.
Let $R$ be a Boolean ring (i.e. $\forall r\in R, \exists n>1: r^n=r$).
Prove that ...
0
votes
1
answer
101
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Boolean rings are associative $\mathbb{Z}/2\mathbb{Z}$-algebras
Let $B$ be a boolean ring, that is, for all $x\in B$ we have $x^2 = x$. Then we know a few things about them. First $B$ has characteristic $2$, since taking $x\in B$ we have
$$x+x = (x+x)^2 = x^2 + x^...
1
vote
0
answers
34
views
Given a boolean matrix $M$ what are the matrices formed by replacing $1s$ in $M$ with $0s$ called?
Given two boolean matrices $A$ and $B$ over some common dimensions one can form an order via $A\leq B\iff \forall i,j(A_{i,j}\leq B_{i,j})$ under this order, what would the matrix $A$ be called in ...
2
votes
1
answer
74
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Why is the boolean "OR" operator denoted as "+"?
I learnt boolean algebra as part of a computer hardware course where the focus was very much on using it as a foundation for creating digital logic blocks out of gates, so there was very early on ...
2
votes
1
answer
49
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How can I define a module over a Boolean ring?
I want to give an example of a module over a Boolean ring $R$ (in particular, the power set of a set $X$ under symmetric difference and set intersection).
I thought of defining a map $(Y, m) \...
4
votes
3
answers
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Help understanding why finite Boolean rngs must be rings
I'm working through the exercises in Introduction to Boolean Algebra by Halmos and Givant. Looking to show the following, an exercise from the first chapter: every finite Boolean rng must have a unit. ...
0
votes
1
answer
583
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If $R$ is a Boolean ring which is in fact a field, then it must be isomorphic to $\mathbb Z / 2 \mathbb Z$ [duplicate]
Suppose $R$ is a Boolean ring ($\forall r \in R, r^2 =r$) which is in fact a field. Show it then must be isomorphic to $\mathbb Z / 2 \mathbb Z$.
I already managed to show that every Boolean ring is ...
2
votes
1
answer
221
views
Spectrum of a ring in which $a^p=a$ for all $a$ and prime number $p$
It is known the result that spectrum of a boolean ring is zerodimensional and compact topological space, e.g. has a base with clopen sets and satisfies Haussdorf condition. It is asked if this result ...
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vote
2
answers
430
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Let R be a ring in which $x^2=x$ for all x ε R. (a) Prove that $x + x = 0$ for for all x ε R. (b) Prove that R is commutative. [duplicate]
I am aware this question has been asked many times but I'm still struggling to understand a few things.
Let R be a ring in which $x^2=x$ for all x ε R.
(a) Prove that $x + x = 0$ for for all x ε R.
...
2
votes
1
answer
38
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Irreducibility for boolean ring?
Every element in $x \in A$ in a commutative bolean ring $A$ is by definition equal to $xx$, and so therefore there are no irreducible elements in the usual sense. So I ask, how might one define ...
1
vote
1
answer
181
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How to test whether an element is in a principal ideal of a ring without enumerating all elements of the ring?
Suppose we have a finite, boolean ring $A$ induced by a finite, commutative, boolean monoid $X$ containg $0$ as in:
this question. You only need the first few paragraphs of that long post.
Suppose I ...
0
votes
1
answer
73
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What is an elegant way of defining complement of an element in this ring?
About the ring: $R$ is a commutative boolean ring with $1$ in which for each $x \in R$, $x + x = 0$. There is a partial order on elements of $R$ written $x \leqslant y \iff xy = y$. The ordering ...
1
vote
0
answers
95
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Finite Boolean ring with $1 \neq 0$ is isomorphic to $\mathbb{Z}_2\times \mathbb{Z}_2 \times \dots \times \mathbb{Z}_2$ [duplicate]
Let $R$ be a finite Boolean ring with $1 \neq 0$. Show that $R\cong \mathbb{Z}_2\times \mathbb{Z}_2 \times \dots \times \mathbb{Z}_2$.
This is exercise 2 on p267 in the book abstract algebra of ...
1
vote
2
answers
575
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Commutativity of Boolean ring
I could not prove that "Every Boolean ring is commutative", but I found it on the Internet. I am giving the idea of the proof that I "learned".
Let $R$ be the Boolean ring.
We can easily prove that $...
1
vote
1
answer
77
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Equivalent properties of a proper ideal of a generalized boolean algebra
I do not understand the item c) of the following question, the exercise 9 from section 1.2 from the book "Lattice-ordered Rings and Modules" from Stuart A. Steinberg:
A generalized boolean algebra is ...
2
votes
1
answer
93
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Proving associativity of a certain binary aperation in any complemented distributive lattice
If, in a Boolean lattice $(X,\vee,\wedge,0,1,')$ (i.e. a complemented distributive lattice), we define $x+y=(x'\wedge y)\vee(x\wedge y')$, is there an elegant way to prove that $(x+y)+z=x+(y+z)$ ...
2
votes
1
answer
98
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Rings in which each element is a sum of $n$ commuting idempotents
Let $n$ be a nonnegative integer. Let $R$ be a nonunital ring such that every element of $R$ is a sum of $n$ pairwise commuting idempotents. (As usual, the class of nonunital rings includes the class ...
0
votes
1
answer
77
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Shall we call this relation an "isomorphism"?
This is a short question:
Assume the values: $\mathbf{True}$, $\mathbf{False}$
and the logic symbols: $\land,\lor$
Is $\mathbf{True}$, $\mathbf{False}$ under $\land,\lor \,$ isomorphic to $\...
7
votes
2
answers
506
views
An $m$-ary function that represents all $n$-ary functions
Motivation
It is well-known that any binary operator $*$ on the boolean ring $\{0,1\}$ can be represented using only one of the $\operatorname{NAND}$ and $\operatorname{NOR}$ operators. For example,...
2
votes
1
answer
200
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GRE 9768 #60 Boolean non-commutative rings: Prove $(-s)^2=s^2$ without commutativity.
GRE 9768 #60
Ian Coley's approach is to prove $(I)$ and $(I) \implies (II) \implies (III)$
In proving $(I)$, how do we prove $$(-s)^2=s^2$$ without commutativity (but with $s=s^2$, if need ...
2
votes
1
answer
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GRE 9768 #60 1. Does $(s+t)^2=s^2+t^2$ imply $s+s=0$? 2. Idempotent matrices do not form a ring?
GRE 9768 #60 on what appears to be Boolean rings:
Ian Coley's approach is to prove $(I)$ and $(I) \implies (II) \implies (III)$
I think $(II) \implies (I)$. My attempt:
$$(s+t)^2=s^2+t^2 \...
-1
votes
1
answer
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Set Ring and Algebraic Ring
Let $\mathscr{R}$ be a ring of sets and define set operations $\odot=\text{multiplication}$ and $\oplus=\text{addition}$ by $$E\odot F=E\cap F$$ and $$E\oplus F=E\triangle F$$
then $\mathscr{R}$ is ...
1
vote
2
answers
533
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Boolean algebra/ring: Compute product of sum of combinations of variables
Let's say I have a set of variables $a_1, ... ,a_n \in \{0, 1\}$ and a boolean algebra where multiplication is $\land$ and sum is $\oplus$ (exclusive or). This is like in bit operations in computers.
...
0
votes
2
answers
72
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On Boolean algebras and Atoms
I know plenety of questions have been made around this topics, but i've got an specific one. If $\mathfrak A$ Is an infinite boolean algebra, and $C$ is a finite subset of atoms in $\mathfrak A$, then ...
0
votes
1
answer
205
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Are these boolean rings integral domains?
Let X be a set and let P(X) denote the Boolean ring whose elements are the subsets of X, with addition being symmetric difference and multiplication being intersection.
Is P({1}) an integral domain?
...
0
votes
1
answer
1k
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Show that a Boolean ring is a commutative ring. [closed]
I have a question about (https://math.stackexchange.com/q/10279)'s proof to this. I also asked as a comment but I am unsure whether it will be replied to since the post was made 8 years ago?
My ...
1
vote
1
answer
166
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How to prove convergence of a sequence of binary numbers
I have a boolean expression with 4 inputs and 1 output, that when iterated onto itself(output->input(s)), the function converges to 1.
How do I go about proving the convergence of a sequence of binary ...
2
votes
1
answer
217
views
A non-Boolean ring without unity with this property
I'm exploring rings that have the following property:
$\rule{10cm}{0.4pt}$
For all $x \in R$, and for all $n \in \mathbb{N}$, there exists $y \in R$ such that $\sum_{i=1}^{n} x = y \cdot x$.
$\rule{...
2
votes
1
answer
47
views
Expressing real function algebraically for every point in its domain
Let's say that f(x) is a function with its domain called $A$ with its codomain labeled $B$. The indicator function $I_{\{p\}}(x)$ has a value of the multiplicative identity, $1$, when $x=p$, and $0$ ...
0
votes
1
answer
886
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Compliment multiplication Compliment
Since, $a+a'=1$ and $a.a'=0$ (Boolean Algebra complement laws), where $a$ is a variable and $a'$ is its complement. Can you please explain what $a'.a'=$ would be?
Also, please prove your result as ...