a visible list, the list of entries {w_i, w_j, ...}
Description
The entries of w are numbered starting with 0. If i is negative, then the i-th entry counting from the end is provided. If i is out of range, an error is signaled.
i1 : w = {a,b,c,d,e,f,g,h}
o1 = {a, b, c, d, e, f, g, h}
o1 : List
i2 : w_{1,3,4}
o2 = {b, d, e}
o2 : List
i3 : w_{-1,-2,-3}
o3 = {h, g, f}
o3 : List
We can use this operation to compute composition of permutations represented as lists.