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 was the chairman of the Dutch Pacifist Socialist Party (PSP). Alongside Richard Bird, he co-developed Bird–Meertens formalism and received the Meertens number from him.