# The endpoints of an interval: left right

### 5.38.2 The endpoints of an interval: left right

The left and right commands can find the left and right endpoints of an interval. (See Section 5.15.3, Section 5.40.6, Section 5.37.1, Section 5.55.4 and Section 5.55.5 for other uses of left and right.)

- left and right take one argument:
  I, an interval.
- left(I) returns the left endpoint of the interval I.
- right(I) returns the right endpoint of the interval I.

#### Examples.

- Input:
  left(i[2,5])
  Output:

  2.00000000000000

- Input:
  right(i[2,5])
  Output:

  5.00000000000000