[32] It is necessary to make this distinction for a space may be flat and yet only semi-Euclidean, as will be understood in later chapters when discussing space-time.
[33] The
’s were also the components of a tensor.
[34] We may note that the geometry, hence the nature, of a space is fully determined only when we express it in terms of the Riemann-Christoffel tensor
. Thus
at every point denotes perfectly flat or homaloidal space;
