Let H : <m×<n → <n be a locally Lipschitz function in a neighborhood of (ȳ, x̄) and H(ȳ, x̄) = 0 for ȳ ∈ <m and x̄ ∈ <n. The implicit function theorem in the sense of Clarke [1, 2] says that if πx∂H(ȳ, x̄) is of maximal rank, then there exist a neighborhood Y of ȳ and a Lipschitz function G(·) : Y → <n such that G(ȳ) = x̄ and for every y in Y , H(y,G(y)) = 0. In this paper, we shall further show tha...

for some real number X, the symbol V denoting the lattice least upper bound. Any ring R is regular [10] if for each xER there is an xaER such that xx°x = x. It is evident that every regular F-ring R contains a maximal bounded sub-F-ring R, the F-ring of all xER satisfying equation (1.1). The relationship between a regular F-ring and its maximal bounded sub-F-ring is analogous to that between th...

Let R be a nil ring. We prove that primitive ideals in the polynomial ring R[x] in one indeterminate over R are of the form I [x] for some ideals I of R. All considered rings are associative but not necessarily have identities. Köthe’s conjecture states that a ring without nil ideals has no one-sided nil ideals. It is equivalent [4] to the assertion that polynomial rings over nil rings are Jaco...

Suppose that X is an infinite set with |X| ≥ q ≥ א0 and I X is the symmetric inverse semigroup defined on X. In 1984, Levi and Wood determined a class of maximal subsemigroups MA using certain subsets A of X of the Baer-Levi semigroup BL q {α ∈ I X : dom α X and |X \ Xα| q}. Later, in 1995, Hotzel showed that there are many other classes of maximal subsemigroups of BL q , but these are far more...

Let (R; m) be a local (Noetherian) ring. The main result of this paper asserts the existence of a local extension ring S of R such that (i) S dominates R, (ii) the residue eld of S is a nite purely transcendental extension of R=m, (iii) dim(S) 1. In addition, it is shown that S can be obtained so that either mS is the maximal ideal of S or S is a localization of a nitely generated R-algebra.