Mathematician/philosopher/historian/typographer.

Author of #OpenAccess books:
• ‘Form & Number: A History of Mathematical Beauty’ [https://archive.org/details/cain_formandnumber_ebook_large];
• an annotated edition, with commentary, of G.H. Hardy’s ‘A Mathematician’s Apology’ [https://archive.org/details/hardy_annotated];
• ‘Nine Chapters on the Semigroup Art’ [https://archive.org/details/cain_semigroups_a4_screen]