1. Proof theory for heterogeneous logic combining formulas and diagrams: proof normalization

   • Ryo Takemura

   OriginalPaper 24 February 2021 Pages: 783 - 813

   

2. Generalised stability of ultraproducts of finite residue rings

   • Ricardo Isaac Bello Aguirre

   OriginalPaper 06 February 2021 Pages: 815 - 829

   

3. Short note: Least fixed points versus least closed points

   • Gerhard Jäger

   OriginalPaper Open access 08 February 2021 Pages: 831 - 835

4. Hereditary G-compactness

   • Tomasz Rzepecki

   OriginalPaper 14 February 2021 Pages: 837 - 856

   

5. Monotonic modal logics with a conjunction

   • Paula Menchón
   • Sergio Celani

   OriginalPaper 01 April 2021 Pages: 857 - 877

6. The theories of Baldwin–Shi hypergraphs and their atomic models

   • Danul K. Gunatilleka

   OriginalPaper 05 April 2021 Pages: 879 - 908

7. The automorphism group and definability of the jump operator in the \(\omega \)-enumeration degrees

   • Hristo Ganchev
   • Andrey C. Sariev

   OriginalPaper 01 April 2021 Pages: 909 - 925

8. On the spectra of cardinalities of branches of Kurepa trees

   • Márk Poór

   OriginalPaper 28 June 2021 Pages: 927 - 966

9. Factorizing the \(\mathbf {Top}\)–\(\mathbf {Loc}\) adjunction through positive topologies

   • Francesco Ciraulo
   • Tatsuji Kawai
   • Samuele Maschio

   OriginalPaper Open access 21 April 2021 Pages: 967 - 979

10. Pointwise complexity of the derivative of a computable function

    • Ethan McCarthy

    OriginalPaper 16 April 2021 Pages: 981 - 994

    

11. Proof-theoretic uniform boundedness and bounded collection principles and countable Heine–Borel compactness

    • Ulrich Kohlenbach

    OriginalPaper Open access 26 April 2021 Pages: 995 - 1003

12. The abstract type of the real numbers

    • Fernando Ferreira

    OriginalPaper 23 April 2021 Pages: 1005 - 1017

    

13. Definable connectedness of randomizations of groups

    • Alexander Berenstein
    • Jorge Daniel Muñoz

    OriginalPaper 05 May 2021 Pages: 1019 - 1041