Sollya User's Manual

Name:

- subtraction function

Usage:

function1 - function2 : (function, function) -> function interval1 - interval2 : (range, range) -> range interval1 - constant : (range, constant) -> range interval1 - constant : (constant, range) -> range - function1 : function -> function - interval1 : range -> range

Parameters:

function1 and function2 represent functions
interval1 and interval2 represent intervals (ranges)
constant represents a constant or constant expression

Description:

- represents the subtraction (function) on reals. The expression function1 - function2 stands for the function composed of the subtraction function and the two functions function1 and function2, where function1 is the subtrahend and function2 the subtractor.
- can be used for interval arithmetic on intervals (ranges). - will evaluate to an interval that safely encompasses all images of the subtraction function with arguments varying in the given intervals. Any combination of intervals with intervals or constants (resp. constant expressions) is supported. However, it is not possible to represent families of functions using an interval as one argument and a function (varying in the free variable) as the other one.
- stands also for the negation function.

Example 1:

> 5 - 2;
3

Example 2:

> x - 2;
-2 + x

Example 3:

> x - x;
0

Example 4:

> diff(sin(x) - exp(x));
cos(x) - exp(x)

Example 5:

   > [1;2] - [3;4];
   [-3;-1]
   > [1;2] - 17;
   [-16;-15]
   > 13 - [-4;17];
   [-4;17]

Example 6:

   > -exp(x);
   -exp(x)
   > -13;
   -13
   > -[13;17];
   [-17;-13]