let n be Nat; :: thesis: for ap, bm, cp, dm being nonpair-yielding FinSeqLen of n
for s being State of (n -BitFTA1Circ (ap,bm,cp,dm)) holds Following (s,4) is stable

let ap, bm, cp, dm be nonpair-yielding FinSeqLen of n; :: thesis: for s being State of (n -BitFTA1Circ (ap,bm,cp,dm)) holds Following (s,4) is stable
let s be State of (n -BitFTA1Circ (ap,bm,cp,dm)); :: thesis: Following (s,4) is stable
set S1 = n -BitFTA1Layer1Str (ap,bm,cp);
set S2 = n -BitFTA1Layer2Str (ap,bm,cp,dm);
set C1 = n -BitFTA1Layer1Circ (ap,bm,cp);
set C2 = n -BitFTA1Layer2Circ (ap,bm,cp,dm);
set S = n -BitFTA1Str (ap,bm,cp,dm);
set C = n -BitFTA1Circ (ap,bm,cp,dm);
A1: n -BitFTA1Str (ap,bm,cp,dm) = (n -BitFTA1Layer1Str (ap,bm,cp)) +* (n -BitFTA1Layer2Str (ap,bm,cp,dm)) by Th16;
A2: n -BitFTA1Circ (ap,bm,cp,dm) = (n -BitFTA1Layer1Circ (ap,bm,cp)) +* (n -BitFTA1Layer2Circ (ap,bm,cp,dm)) by Th17;
A3: n -BitFTA1Layer1Circ (ap,bm,cp) tolerates n -BitFTA1Layer2Circ (ap,bm,cp,dm) by CIRCCOMB:60;
A4: the Sorts of (n -BitFTA1Layer1Circ (ap,bm,cp)) tolerates the Sorts of (n -BitFTA1Layer2Circ (ap,bm,cp,dm)) by A3, CIRCCOMB:def 3;
reconsider t = s as State of ((n -BitFTA1Layer1Circ (ap,bm,cp)) +* (n -BitFTA1Layer2Circ (ap,bm,cp,dm))) by A2;
reconsider s1 = t | the carrier of (n -BitFTA1Layer1Str (ap,bm,cp)) as State of (n -BitFTA1Layer1Circ (ap,bm,cp)) by A4, CIRCCOMB:26;
reconsider s2 = (Following (t,2)) | the carrier of (n -BitFTA1Layer2Str (ap,bm,cp,dm)) as State of (n -BitFTA1Layer2Circ (ap,bm,cp,dm)) by A4, CIRCCOMB:26;
A5: InputVertices (n -BitFTA1Layer1Str (ap,bm,cp)) misses InnerVertices (n -BitFTA1Layer2Str (ap,bm,cp,dm)) by Th18;
A6: Following (s1,2) is stable by Th19;
A7: Following (s2,2) is stable
proof end;
Following (t,(2 + 2)) is stable by CIRCCOMB:60, A5, A6, A7, CIRCCMB2:19;
hence Following (s,4) is stable by A1, A2; :: thesis: verum