ABSTRACT
This book is in two = (zero, one | } parts. In this zeroth part, our topic is the notion of number. As examples we have the finite numbers 0 ,1 ,2 ,..., - 1, 1, y/2, n ,.. .; infinite numbers such as w (the first infinite ordinal); and also infinitesimal numbers such as l/ai. If we were to adopt the axiom of choice, then the infinite cardinal numbers like N0 could be identified with the least corresponding ordinal numbers, so that we can regard these too as part of our system (although the arithmetic is different).
