Abstract (EN):
Let R be the pseudovariety of all finite monoids whose principal right ideals have a unique generator, let L be its dual, and let J = R boolean AND L. Using the word problem for free pro-J monoids, it is shown that the bilateral semidirect product SI ** J is local, where SI denotes the pseudovariety of all finite semilattices. The global of the pseudovariety R boolean OR L is also computed and it is shown that this join is not local.
Language:
English
Type (Professor's evaluation):
Scientific