Realizability: a historical Essay. *Mathematical Structures in Computer Science*
(2002),12,pp.239-263.

Relative and Modified Relative Realizability, with Lars Birkedal.*Annals of Pure and
Applied Logic* 118 (2002),pp.115-132.

Ordered PCA's,
with Pieter Hofstra. *Mathematical Proceedings of the Cambridge Philosophical Society*, 2003,134,pp.445-463.

A Partial Analysis of Modified Realizability. *Journal of Symbolic Logic* 69
(2004),2,pp.421-429.

Well-foundedness in Realizability. With Martin Hoffman and Thomas Streicher.*Archive for Mathematical Logic* **45** (2006), 795-805.

A Coinductive Definition of Repletion.Note.

Review of "Sheaves, Games and Model Completions" by S. Ghilardi and M. Zawadowski. *Bulletin of
Symbolic Logic*,10 (2004),2,216-217.

Note on the Independence of Premiss principle.

Filtered Colimits in the Effective Topos. *Journal of Pure and Applied
Algebra* **205** (2006), 446-451.

Algebraic Set Theory and the Effective Topos. With Claire Kouwenhoven. *Journal of
Symbolic Logic* 70 (2005),3, pp.879--890.

A general form of relative recursion, October 2005. *Notre Dame Journal of
Formal Logic* **47** (2006), no.3, 311-318

Review of "From Sets and Types...", July 2006. *Bulletin of
Symbolic Logic* **12** (2006),no.4,611-612

Review of Ponstein's "Nonstandard Analysis" (in Dutch; Nieuw Archief voor Wiskunde ser.5,vol.7,nr.3, september 2006, p.218)

.Slides of invited tutorial *What is Synthetic Domain Theory?*, FMCS 2006, Kananaskis (Canada)

Partial Combinatory Algebras of Functions, May 2009. Notre Dame Journal of Formal Logic 52 (2011),4,431-448.

A Notion of Homotopy for the Effective Topos, March 2010

Review of Simpson's "Subsystems of Second Order Arithmetic" (in Dutch, for Nieuw Archief voor Wiskunde), May 2011

Arithmetic is Categorical, May 2011. With Benno van den Berg.

Basic Subtoposes of the Effective Topos, with Sori Lee. Annals of Pure and Applied Logic **164** (2013), 866-883.

Realizability with a Local Operator of A.M. Pitts, Theoretical Computer Science 546 (2014), 237-243.

Review of Schwichtenberg and Wainer's "Proofs and Computations" (in Dutch), Nieuw Archief voor Wiskunde, december 2013, 290--291.

Effective Operations of Type 2 in PCAs, with Eric Faber. Computability 5 (2016), pp.127-146.

More on Geometric Morphisms between Realizability Toposes, with Eric Faber. *Theory and Applications of Categories* vol. 29, no. 30 (2014), pp. 874-895.

Review of "Homotopy Type Theory", Bulletin of Symbolic Logic 20 (4) (December 2014), pp. 497-500.

Defining Functors by Well-founded Recursion, note.

Classical and Relative Realizability, with Tingxiang Zou. *Theory and Applications of Categories* 31 (2016), 22, pp.571--593.

Extensions of Scott's Graph Model and Kleene's Second Algebra, with Niels Voorneveld. *Indagationes Mathematicae* 29 (2018), pp.5--22.

Back to base.