On mobs with certain group-like properties

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1965

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Virginia Polytechnic Institute

Abstract

Topological groupoids with"approximate" inverses are studied. In the compact case, these"approximate" inverses turn out to be true inverses.

Examples of groupoids wL:h"approximate" inverses are given in the section dealing with function spaces.

Using the classical construction of Haar as a guide, we succeed in obtaining a (non-trivial) regular, right-invariant measure over a locally compact left group satisfying the conditions:

a) open sets are preserved by left translation b) each group component is open.

In the section dealing with integrals, we consider a compact metric topological semigroup that is right simple 3nd possesses a right contractive metric (ρ(xz,yz) ≤ ρ(x,y)). It is shown that such a structure always carries a non-trivial right-invariant integral. Throughout the entire development, associativity is invoked only once.

The investigation concludes with a section dealing with sufficient conditions under which binary-topological systems become topological groups. A mob-group is defined to be a To-space which is also an algebraic group. A theorem in the last section states that a mob-group is a topological group iff given any open set W about the identity, W ∩ W⁻¹ has non-void interior.

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