
12 Numbers 12.1 Number Concepts 12.1.4 Floatingpoint Computations 12.1.4.1 Rule of Float and Rational Contagion
12.1.4.1.1 Examples of Rule of Float and Rational Contagion
;;;; Combining rationals with floats.
;;; This example assumes an implementation in which
;;; (floatradix 0.5) is 2 (as in IEEE) or 16 (as in IBM/360),
;;; or else some other implementation in which 1/2 has an exact
;;; representation in floating point.
(+ 1/2 0.5) 1.0
( 1/2 0.5d0) 0.0d0
(+ 0.5 0.5 1/2) 0.5
;;;; Comparing rationals with floats.
;;; This example assumes an implementation in which the default float
;;; format is IEEE singlefloat, IEEE doublefloat, or some other format
;;; in which 5/7 is rounded upwards by FLOAT.
(< 5/7 (float 5/7)) true
(< 5/7 (rational (float 5/7))) true
(< (float 5/7) (float 5/7)) false
