منابع مشابه
Invertible Rings and Axiomatic Algebra
Assume λ ≥ 0. Every student is aware that Ω > 0. We show that ε(Yβ,ψ) ∈ YC ,l. Thus the work in [14] did not consider the Smale case. Thus this could shed important light on a conjecture of Poisson.
متن کاملOn Retracts, Absolute Retracts, and Folds in Cographs
Let G and H be two cographs. We show that the problem to determine whether H is a retract of G is NP-complete. We show that this problem is fixed-parameter tractable when parameterized by the size of H. When restricted to the class of threshold graphs or to the class of trivially perfect graphs, the problem becomes tractable in polynomial time. The problem is also soluble in linear time when on...
متن کاملAlgebra Handout 1: Rings, Fields and Groups
(A1) a+ b = b+ a (commutativity of addition); (A2) (a+ b) + c = a+ (b+ c) (associativity of addition); (A3) There exists an element, called 0, such that 0 + a = a. (additive identity) (A4) For x ∈ R, there is a y ∈ R such that x+y = 0 (existence of additive inverses). (M1) (a · b) · c = a · (b · c) (associativity of multiplication). (M2) There exists an element, called 1, such that 1 · a = a · ...
متن کاملCubic Rings and the Exceptional Jordan Algebra
In a previous paper [EG] we described an integral structure (J, E) on the exceptional Jordan algebra of Hermitian 3 × 3 matrices over the Cayley octonions. Here we use modular forms and Niemeier’s classification of even unimodular lattices of rank 24 to further investigate J and the integral, even lattice J0 = (ZE) in J . Specifically, we study ring embeddings of totally real cubic rings A into...
متن کاملRetracts and Q-independence
A non-empty set X of a carrier A of an algebra A is called Q-independent if the equality of two term functions f and g of the algebra A on any finite system of elements a1, a2, . . . , an of X implies f(p(a1), p(a2), . . . , p(an)) = g(p(a1), p(a2), . . . , p(an)) for any mapping p ∈ Q. An algebra B is a retract of A if B is the image of a retraction (i.e. of an idempotent endomorphism of B). W...
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ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 2014
ISSN: 0022-4049
DOI: 10.1016/j.jpaa.2014.01.006