TURING, Alan. 'Finite approximations to lie groups.' Offprint from: Annals of Mathematics, vol. 39, no. 1. Princeton, NJ: 1938. 8° (255 x 175mm). 8pp., 105-111. Original wrappers, stapled (faint spotting and creasing to upper wrapper, staples rusted). Provenance: R.O. Gandy (some occasional pencil marginalia). [With:] -- 'The extension of a group.' Offprint from: Compositio Mathematica, vol. 5, fascicle 3. Groningen: 1938. 8° (248 x 170mm). 12pp., 358-367. Original wrappers, with overlay printing of Turing's name and title to upper cover, stapled (faint sunning to extremities, staples rusted, faint creasing to top corner, extending throughout).

TURING, Alan. 'Finite approximations to lie groups.' Offprint from: Annals of Mathematics, vol. 39, no. 1. Princeton, NJ: 1938. 8° (255 x 175mm). 8pp., 105-111. Original wrappers, stapled (faint spotting and creasing to upper wrapper, staples rusted). Provenance: R.O. Gandy (some occasional pencil marginalia). [With:] -- 'The extension of a group.' Offprint from: Compositio Mathematica, vol. 5, fascicle 3. Groningen: 1938. 8° (248 x 170mm). 12pp., 358-367. Original wrappers, with overlay printing of Turing's name and title to upper cover, stapled (faint sunning to extremities, staples rusted, faint creasing to top corner, extending throughout).

TURING ON GROUP THEORY. 'A new departure, which arose through contact with von Neumann. It was a problem suggested by the emigré Polish mathematician S. Ulam: that of asking whether continuous groups could be approximated by finite groups, rather like approximating a sphere by polyhedra. Von Neumann had passed the problem to Alan, who successfully dealt with it by April, when it was submitted. This was fast work, although as he had shown that continuous groups could not in general be approximated in this way, it was a rather negative result.' Hodges pp.129-130. (2)