\\ Vector representing a function {1,...,n}->{1,...,n}
\\ given by cycle c. Read: vector from cycle.
t_vfc (c,n) = {my (m=#c,j);
vector(n,i, if (j=t_pos(i,c), c[j%m+1],i))}

\\ Vector of cycle from set with respect to permutation p.
t_vocfs (A,p) = {my (positions);
positions=Set(apply(i->t_pos(i,p),A));
vector(#A,i,p[positions[i]])}