2. (T List) List
3. u : T List
4. v : (T List) List
5.
n:
||concat(v)||.
5.
m:||v||.
5. ||concat(firstn(m;v))||
n
5. & n-||concat(firstn(m;v))||<||v[m]||
5. & concat(v)[n] = v[m][(n-||concat(firstn(m;v))||)]
6. n :
||u @ concat(v)||
7. n<||u||
8. m :
(||v||+1)
(||concat(firstn(m;[u / v]))||n
(& n-||concat(firstn(m;[u / v]))||<||[u / v][m]||
(& (u @ concat(v))[n] = [u / v][m][(n-||concat(firstn(m;[u / v]))||)])
Prop
