A set of postulates for fields
Norbert Wiener · Transactions of the American Mathematical Society · 1920
Whatever x may be, there is a P-element y such that x @ (y @ y) is not a X-element.2. If x and y are P-elements, but x @ y is not a K-element, there is a Kelement z such that y = z @z.3. Whenever x and y are distinct P-elements, either x@yory@xisa PJ-element.4. Whenever x, y, «, v, and their indicated combinations are Ä-elements, and x @ y = « @ v, then x