
This function returns the spacing of model numbers with the same kind as X, in the vicinity of X.
If X is not a model number (for example, if X is an IEEE subnormal number), SPACING is the value for the nearest model number to X; if X is an IEEE infinity or NaN, the result is a NaN.
For nonzero finite numbers, this is equal to REAL(RADIX(X),KIND(X))**MAX(EXPONENT(X)DIGITS(X),MINEXPONENT(X)1).
Note that the spacing of model numbers in the vicinity of zero is TINY(X).
Like many intrinsic functions, this is elemental; the result has the same shape as X, with the operation being applied elementwise.

