6.1.6  Getting an element of a sequence or a list

The elements of a sequence have indices beginning at 0 in Xcas mode and 1 in other modes (see Section 2.5.2).

You can get the an element of index n of a sequence or list by following the sequence or list with [n] (see Section 3.2.4).

(Note that head(S) does the same thing as S[0].)

Examples

For lists, the at command can also be used to get the element at a specific position.

• at takes two arguments:
  • L, a list.
  • n, an integer.
• at(L,n) returns the element of S with index n.

Note.

at cannot be used for sequences, since the second argument would be merged with the sequence.

Example

or: