- I is an interval.
- x is a real number.

- Returns the lower bound of the interval I. Each bound of an interval has its own precision, so this command is exact, even if the current precision is too small to represent the bound.
- When called on a real number x, inf considers it as an interval formed of a single point: [x, x]. In other words, inf behaves like the identity.

1

> inf(0);

0

> I=[0.111110000011111_2; 1];

> inf(I);

1.11110000011111_2 * 2^(-1)

> prec=12!;

> inf(I);

1.11110000011111_2 * 2^(-1)