Dines Bjørner. Towards Posit & Prove Calculi for Requirements Engineering and Software Design: In Honour of the Memory of Professor Ole-Johan Dahl. In Olaf Owe, Stein Krogdahl, Tom Lyche, editors, From Object-Orientation to Formal Methods, Essays in Memory of Ole-Johan Dahl. Volume 2635 of Lecture Notes in Computer Science, pages 58-82, Springer, 2004. [doi]