MSS. Eng. misc. b. 301/J.35-41

Dana Scott and Strachey collaborated closely from 1969 until Strachey's death. In December 1971, Strachey wrote: 'In September 1969 Dana Scott came to Oxford and as a result of discussion about the formal semantics produced his theory of continuous lattices and was able to give for the first time a set-theoretic model of the λ-calculus. To my mind this work has changed the whole basis of the theory of computing and promises to provide the sound mathematical foundation which has so far been lacking. There is a great deal of work still to be done in applying this to the problems of actual programming languages and developing general theorems and techniques for providing properties of programs. This work and the practical work on systems continue to form my main pre-occupation.'

The collaborative work was often carried on by correspondence when Strachey or Scott were abroad, and these frequent and lengthy exchanges enabled the growth of ideas to be charted. Though other matters are discussed, such as travel and conference plans, publication and circulation arrangements, appointments, etc., the bulk of the correspondence remains primarily technical in content.

Papers discussed, often by their initials, are 'Outline of a Mathematical Theory of Computation' (OMTC), 'Lattice of Flow Diagrams' (LFD), 'Towards a Mathematical Semantics for Computer Languages' (TMSCL). Copies of letters from colleagues, publishers, etc. are sometimes included. The 1970 correspondence was kept by Strachey in 2 loose-leaf ring binders, with an (incomplete) index by him (MS. Eng. misc. b. 301/J.36 and MS. Eng. misc. b. 301/J.37).