Born in The Netherlands, June 1956. Has a PhD in logical-semantics (University of Amsterdam, March 1992, supervisor: Johan van Benthem). Studied Philosophy, Logic, and Information science (University of Amsterdam, October1987, cum laude). Has published several articles on generalized quantification in top-level journals and books. Has published his book Passed over in Silence, on Wittgenstein’s Tractatus and its system (June 2011). Plays alto-saxophone in the jazz saxophone quartet SKOL. Occasionally writes poems.