1 | 1. Alph: Type 2. S: ActionSet(Alph) 3. si: S.car 4. nn:  5. f: nn Alph 6. g: Alph  nn 7. Fin(S.car) 8. InvFuns( nn; Alph; f; g) 9. n:  RL:{y:{x:(S.car*)| 0 < ||x|| & ||x|| n+1 }| y[(||y||-1)] = si }.
( s:S.car. ( w:Alph*. (S:w si) = s)  mem_f(S.car;s;RL))
||RL|| = n+1
& ( i: ||RL||, j: i. RL[i] = RL[j])
& ( s:S.car. mem_f(S.car;s;RL)  ( w:Alph*. (S:w si) = s))
& ( k: .
k nn 
( RLa:S.car*.
( i:{1..||RL|| }, a:Alph. mem_f(S.car;S.act(a,RL[i]);RL) mem_f(S.car;S.act(a,RL[i]);RLa))
& ( a:Alph. g(a) < k  mem_f(S.car;S.act(a,hd(RL));RL) mem_f(S.car;S.act(a,hd(RL));RLa))
& ( s:S.car. mem_f(S.car;s;RLa)  ( w:Alph*. (S:w si) = s)))) |