The elements of sequences and lists are indexed starting from 0 in Xcas syntax mode and from 1 in all other syntax modes (see Section 2.5.2). To access an element of a list or a sequence, follow the list with the index between square brackets.
| L:=[2,5,1,4] |
|
| L[1] |
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To access the last element of a list or sequence, you can put -1 between square brackets.
| L[-1] |
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If you want the indices to start from 1 in Xcas syntax mode, you can enter the index between double brackets.
| L[[1]] |
|