Section 8,4,7: REAL

 A REAL (REAL*4) constant can be a basic real constant (with or
 without a decimal exponent) or an integer constant followed by a
 decimal exponent.  A basic real constant has one of these forms:

    s.nn            s is an optional sign
    snn.nn          nn is a string of decimal digits
    snn.

 A decimal exponent has the form:

    Esnn            s is an optional sign
                    nn is an integer constant

 The approximate range of a nonzero REAL constant is 1.175E-38 to
 3.403E38 (S_floating).

 S_floating computational results smaller than 1.17549429E-38 are
 denormalized numbers that gradually underflow and lose precision,
 until they reach approximately 1.40129846E-46.  You cannot write a
 constant for a denormalized number.