1. Bi-atomic classes of positive semirings

   • Nicholas R. Baeth
   • Scott T. Chapman
   • Felix Gotti

   RESEARCH ARTICLE 13 April 2021 Pages: 1 - 23

   

2. The Lawson number of a semitopological semilattice

   • Taras Banakh
   • Serhii Bardyla
   • Oleg Gutik

   RESEARCH ARTICLE Open access 13 May 2021 Pages: 24 - 37

3. Analytic semigroups generated by Dirichlet-to-Neumann operators on manifolds

   • Tim Binz

   RESEARCH ARTICLE Open access 18 May 2021 Pages: 38 - 61

4. Well-posedness and stability of nonautonomous past systems with unbounded operators in the delay term

   • Samir Boujijane
   • Said Boulite
   • Lahcen Maniar

   RESEARCH ARTICLE 04 June 2021 Pages: 62 - 86

5. Partial automorphisms and injective partial endomorphisms of a finite undirected path

   • I. Dimitrova
   • V. H. Fernandes
   • T. M. Quinteiro

   RESEARCH ARTICLE 18 May 2021 Pages: 87 - 105

6. Two weaker variants of congruence permutability for monoid varieties

   • Sergey V. Gusev
   • Boris M. Vernikov

   RESEARCH ARTICLE 02 June 2021 Pages: 106 - 152

   

7. Solution to a problem of FitzGerald

   • Jens Hemelaer
   • Morgan Rogers

   RESEARCH ARTICLE Open access 16 February 2021 Pages: 153 - 164

   

8. From A to B to Z

   • Marcel Jackson
   • Wen Ting Zhang

   RESEARCH ARTICLE 31 March 2021 Pages: 165 - 190

   

9. Partition regularity of polynomial systems near zero

   • Lorenzo Luperi Baglini

   Research Article Open access 30 March 2021 Pages: 191 - 208

10. A note on Hardy’s theorem and rotations

    • Partha Sarathi Patra

    RESEARCH ARTICLE 28 May 2021 Pages: 209 - 220

11. Dense numerical semigroups

    • J. C. Rosales
    • M. B. Branco
    • M. C. Faria

    RESEARCH ARTICLE 06 May 2021 Pages: 221 - 235

    

12. Limit varieties of J-trivial monoids

    • Olga B. Sapir

    RESEARCH ARTICLE 11 May 2021 Pages: 236 - 260

    

13. Special idempotents and projections

    • Paolo Sentinelli

    RESEARCH ARTICLE 18 May 2021 Pages: 261 - 277

    

14. A formula for the conductor of a semimodule of a numerical semigroup with two generators

    • Patricio Almirón
    • Julio José Moyano-Fernández

    SHORT NOTE 30 March 2021 Pages: 278 - 285

    

15. Amenability of semigroups and the Ore condition for semigroup rings

    • V. S. Guba

    Short Note 09 March 2021 Pages: 286 - 290

16. A note on locally compact subsemigroups of compact groups

    • Julio C. Hernández
    • Karl H. Hofmann

    SHORT NOTE 11 February 2021 Pages: 291 - 294

17. Correction to: Numerical semigroups generated by primes

    • Michael Hellus
    • Anton Rechenauer
    • Rolf Waldi

    Correction 10 June 2021 Pages: 295 - 295