PROPER COVERS OF RESTRICTION SEMIGROUPS AND W-PRODUCTS

MÁRIA B. SZENDREI
2012 International journal of algebra and computation  
Each factor semigroup of a free restriction (ample) semigroup over a congruence contained in the least cancellative congruence is proved to be embeddable into a W -product of a semilattice by a monoid. Consequently, it is established that each restriction semigroup has a proper (ample) cover embeddable into such a W -product.
doi:10.1142/s0218196712500245 fatcat:mg57ob6txjayzbr36uthvvh7hm