(r5rs.info.gz) Syntax of numerical constants

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 6.2.4 Syntax of numerical constants
 -----------------------------------
 
 The syntax of the written representations for numbers is described
 formally in section  Lexical structure.  Note that case is not
 significant in numerical constants.
 
 A number may be written in binary, octal, decimal, or hexadecimal by
 the use of a radix prefix.  The radix prefixes are `#b' (binary), `#o'
 (octal), `#d' (decimal), and `#x' (hexadecimal).  With no radix prefix,
 a number is assumed to be expressed in decimal.
 
 A numerical constant may be specified to be either exact or inexact by
 a prefix.  The prefixes are `#e' for exact, and `#i' for inexact.  An
 exactness prefix may appear before or after any radix prefix that is
 used.  If the written representation of a number has no exactness
 prefix, the constant may be either inexact or exact.  It is inexact if
 it contains a decimal point, an exponent, or a "#" character in the
 place of a digit, otherwise it is exact.
 
 In systems with inexact numbers of varying precisions it may be useful
 to specify the precision of a constant.  For this purpose, numerical
 constants may be written with an exponent marker that indicates the
 desired precision of the inexact representation.  The letters `s', `f',
 `d', and `l' specify the use of SHORT, SINGLE, DOUBLE, and LONG
 precision, respectively.  (When fewer than four internal inexact
 representations exist, the four size specifications are mapped onto
 those available.  For example, an implementation with two internal
 representations may map short and single together and long and double
 together.)  In addition, the exponent marker `e' specifies the default
 precision for the implementation.  The default precision has at least
 as much precision as DOUBLE, but implementations may wish to allow this
 default to be set by the user.
 
 
      3.14159265358979F0
             Round to single -- 3.141593
      0.6L0
             Extend to long -- .600000000000000
 

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