REFERRING to the review of Hilbert's “Grundlagen der Geometric,” on p. 394 of No. 2066 of NATURE (June 3), may I point out that the commutative law of addition can be proved without the help of any ...

A Boolean Algebra operation can be related with an electronic circuit in which the inputs and outputs corresponds to the statements of Boolean algebra. Though these circuits may be complicated, they ...

THE existence of various systems of algebra, in which the commutative and associative laws of ordinary algebra are not assumed to be valid, has been known to mathematicians since Hamilton expounded ...