During this time he wrote, with G. T. Kneebone, a graduate textbook on set theory, The Theory of Sets and Transfinite Numbers, as well as numerous papers on ordered structures and Boolean algebras, and in 1977 published Jean Piaget: Psychologist of the Real an exposition and critique of the ideas behind the work of the Swiss child psychologist.
In a Boolean algebra, or more generally a distributive lattice, the median function
algebra | Algebra | Lie algebra | linear algebra | Abstract algebra | Linear Algebra | Lie Algebra | Hopf algebra | Clifford algebra | Boolean operation | Virasoro algebra | Clifford Algebra | Boolean satisfiability problem | Kac-Moody algebra | Hecke algebra | Filtered algebra | Elementary algebra | Computer algebra system | Boolean algebra | Banach algebra | Affine Lie algebra | abstract algebra | spacetime algebra | Ringel–Hall algebra | ring (algebra) | Regular sequence (algebra) | Poisson algebra | module (algebra) | minor (linear algebra) | Map Algebra |
He revisited Boolean axiomatics in 1933, proving that Boolean algebra required but a single binary operation (denoted below by infix '+') that commutes and associates, and a single unary operation, complementation, denoted by a postfix prime.
Karnaugh map, a method to simplify Boolean algebra expressions