set f0 = 1GateCircStr <*> ,((0 -tuples_on BOOLEAN ) --> TRUE );
set g0 = 1GateCircuit <*> ,((0 -tuples_on BOOLEAN ) --> TRUE );
set h0 = [<*> ,((0 -tuples_on BOOLEAN ) --> TRUE )];
let n be Nat; :: thesis: for x, y being FinSeqLen of n
for a, b being set holds
( (n + 1) -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Str x,y) +* (BitGFA1Str a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Circ x,y) +* (BitGFA1Circ a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = GFA1CarryOutput a,b,(n -BitGFA1CarryOutput x,y) )

let x, y be FinSeqLen of n; :: thesis: for a, b being set holds
( (n + 1) -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Str x,y) +* (BitGFA1Str a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Circ x,y) +* (BitGFA1Circ a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = GFA1CarryOutput a,b,(n -BitGFA1CarryOutput x,y) )

let a, b be set ; :: thesis: ( (n + 1) -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Str x,y) +* (BitGFA1Str a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Circ x,y) +* (BitGFA1Circ a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = GFA1CarryOutput a,b,(n -BitGFA1CarryOutput x,y) )
set p = x ^ <*a*>;
set q = y ^ <*b*>;
consider f, g, h being ManySortedSet of NAT such that
A1: n -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = f . n and
A2: n -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = g . n and
A3: f . 0 = 1GateCircStr <*> ,((0 -tuples_on BOOLEAN ) --> TRUE ) and
A4: g . 0 = 1GateCircuit <*> ,((0 -tuples_on BOOLEAN ) --> TRUE ) and
A5: h . 0 = [<*> ,((0 -tuples_on BOOLEAN ) --> TRUE )] and
A6: for n being Nat
for S being non empty ManySortedSign
for A being non-empty MSAlgebra of S
for z being set st S = f . n & A = g . n & z = h . n holds
( f . (n + 1) = S +* (BitGFA1Str ((x ^ <*a*>) . (n + 1)),((y ^ <*b*>) . (n + 1)),z) & g . (n + 1) = A +* (BitGFA1Circ ((x ^ <*a*>) . (n + 1)),((y ^ <*b*>) . (n + 1)),z) & h . (n + 1) = GFA1CarryOutput ((x ^ <*a*>) . (n + 1)),((y ^ <*b*>) . (n + 1)),z ) by Def6;
A7: n -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = h . n by A3, A4, A5, A6, Th15;
A8: (n + 1) -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = f . (n + 1) by A3, A4, A5, A6, Th15;
A9: (n + 1) -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = g . (n + 1) by A3, A4, A5, A6, Th15;
A10: (n + 1) -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = h . (n + 1) by A3, A4, A5, A6, Th15;
A11: len x = n by FINSEQ_1:def 18;
A12: len y = n by FINSEQ_1:def 18;
A13: (x ^ <*a*>) . (n + 1) = a by A11, FINSEQ_1:59;
A14: (y ^ <*b*>) . (n + 1) = b by A12, FINSEQ_1:59;
A15: x ^ <*> = x by FINSEQ_1:47;
A16: y ^ <*> = y by FINSEQ_1:47;
then A17: n -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = n -BitGFA1Str x,y by A15, Th19;
A18: n -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = n -BitGFA1Circ x,y by A15, A16, Th19;
n -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = n -BitGFA1CarryOutput x,y by A15, A16, Th19;
hence ( (n + 1) -BitGFA1Str (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Str x,y) +* (BitGFA1Str a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1Circ (x ^ <*a*>),(y ^ <*b*>) = (n -BitGFA1Circ x,y) +* (BitGFA1Circ a,b,(n -BitGFA1CarryOutput x,y)) & (n + 1) -BitGFA1CarryOutput (x ^ <*a*>),(y ^ <*b*>) = GFA1CarryOutput a,b,(n -BitGFA1CarryOutput x,y) ) by A1, A2, A6, A7, A8, A9, A10, A13, A14, A17, A18; :: thesis: verum