He was chairman of the Dutch Pacifist Socialist Party (PSP) from 1975 until 1981. He was codesigner of the Bird–Meertens formalism, along with Richard Bird, who also gifted him the Meertens number.
From 1975 until 1981, he held the position of chairman for the Dutch Pacifist Socialist Party (PSP). Alongside Richard Bird, he co-created Bird–Meertens formalism and was awarded the Meertens number by him.