1. On non-monotonicity height of piecewise monotone functions

   • Yingying Zeng
   • Lin Li

   OriginalPaper 19 March 2021 Pages: 401 - 414

   

2. The forward order laws for the core inverse

   • Tingting Li
   • Dijana Mosić
   • Jianlong Chen

   OriginalPaper 25 March 2021 Pages: 415 - 431

3. A note on the Choquet type operators

   • Sorin G. Gal
   • Constantin P. Niculescu

   OriginalPaper 11 April 2021 Pages: 433 - 447

4. Convexity properties of functions defined on metric Abelian groups

   • Włodzimierz Fechner
   • Zsolt Páles

   OriginalPaper Open access 25 August 2020 Pages: 449 - 481

5. Gradual transitivity in orthogonality spaces of finite rank

   • Thomas Vetterlein

   OriginalPaper Open access 30 September 2020 Pages: 483 - 503

6. The archetypal equation and its solutions attaining the global extremum

   • Mariusz Sudzik

   OriginalPaper Open access 03 December 2020 Pages: 505 - 526

7. Alienation of Cauchy’s and the quadratic functional equations on semigroups

   • Brahim Fadli

   OriginalPaper 19 March 2021 Pages: 527 - 534

8. Wilson’s functional equation with an anti-endomorphism

   • M. Ayoubi
   • D. Zeglami
   • Y. Aissi

   ReviewPaper 25 August 2020 Pages: 535 - 549

9. Finite dimensional varieties on hypergroups

   • László Székelyhidi
   • Żywilla Fechner

   OriginalPaper Open access 01 February 2021 Pages: 551 - 567

10. Completely monotonic ratios of basic and ordinary gamma functions

    • Christian Berg
    • Asena Çetinkaya
    • Dmitrii Karp

    OriginalPaper 02 January 2021 Pages: 569 - 588

11. Center-like subsets in prime rings with derivations and endomorphisms

    • O. Ait Zemzami
    • L. Oukhtite
    • H. E. Bell

    OriginalPaper 27 February 2021 Pages: 589 - 598

12. Correction to: Embeddability of pairs of weighted quasi-arithmetic means into a semiflow

    • Dorota Głazowska
    • Justyna Jarczyk
    • Witold Jarczyk

    Correction 05 April 2021 Pages: 599 - 600