The left and right portions of a list: left right

### 5.40.6 The left and right portions of a list: left right

The left and right can find the left and right parts of a list. (See Section 5.3.4, Section 5.15.3, Section 5.37.1, Section 5.38.2, Section 5.55.4 and Section 5.55.5 for other uses of left and right.)

- left takes two arguments:
  - L, a list.
  - n, a positive integer.
- left(L,n) returns the first n elements of L.

#### Example.

Input:

left([0,1,2,3,4,5,6,7,8],3)

Output:

⎡ ⎣ | 0,1,2 | ⎤ ⎦

- right takes two arguments:
  - L, a list.
  - n, a positive integer.
- right(L,n) returns the last n elements of L.

#### Example.

Input:

right([0,1,2,3,4,5,6,7,8],4)

Output:

⎡ ⎣ | 5,6,7,8 | ⎤ ⎦