\\ Longest run of subvector u in v.
t_longrun (u,v) = {my (k=0);
for (i=1,#v-#u+1, k=max(k,t_posmultvec(u,v,i))); k}

\\ Number of (overlapping) occurrences of u in v.
t_multvec (u,v) = {my (m,n,f);
m=#u; n=#v; f=0;
for (i=1,n-m+1, f+=(v[i..i+m-1]==u)); f}

\\ Position of first x as element in v from index k. 0 if not present.
t_ pos (x,v,k=1) = {for (i=k,#v, if (v[i]==x, return(i))); 0}

\\ k if u appears k times as subvector in v at position i.
t_posmultvec (u,v,i) = {my (m=#u,k,j);
k=0; j=i+m-1;
while (j<=#v, if (t_repvec(u,k+1)==v[i..j], k++; j+=m, break)); k}

\\ Position of first u as subvector  in v from index k. 0 if not present.
t_posvec (u,v,k=1) = {my (m=#u);
if (m>#v, return(0));
for (i=k,#v-m+1, if (v[i..i+m-1]==u, return (i))); 0}