ANSI Common Lisp   12 Numbers   12.1 Number Concepts

12.1.4 Floating-point Computations

12.1.4.1  Rule of Float and Rational Contagion
12.1.4.2  Rule of Float Approximation
12.1.4.3  Rule of Float Underflow and Overflow
12.1.4.4  Rule of Float Precision Contagion