Sollya User's Manual

Names:

double, D rounding to the nearest IEEE 754 double (binary64).

Description:

double is both a function and a constant.
As a function, it rounds its argument to the nearest IEEE 754 double precision (i.e. IEEE754-2008 binary64) number. Subnormal numbers are supported as well as standard numbers: it is the real rounding described in the standard.
As a constant, it symbolizes the double precision format. It is used in contexts when a precision format is necessary, e.g. in the commands round, roundcoefficients and implementpoly. See the corresponding help pages for examples.

Example 1:

   > display=binary!;
   > D(0.1);
   1.100110011001100110011001100110011001100110011001101_2 * 2^(-4)
   > D(4.17);
   1.000010101110000101000111101011100001010001111010111_2 * 2^(2)
   > D(1.011_2 * 2^(-1073));
   1.1_2 * 2^(-1073)