### 5.40.11 Convert a number to an interval: convert

To convert a number to an interval, the convert command takes two mandatory arguments and one optional argument. The first argument is an expression which evaluates to the desired number, and the second argument is the reserved word interval. The optional argument is an integer greater than 15 giving the desired number of digits.
convert returns the smallest interval containing the value of the expression.
Input:

convert(sin(3)+1, interval)

Output:

[1.14112000805985 .. 1.14112000805990]

Input:

convert(sin(3)+1, interval,20)

Output:

[1.1411200080598672220 .. 1.1411200080598672222]