set f0 = 1GateCircStr <*> ,((0 -tuples_on BOOLEAN ) --> FALSE );
set g0 = 1GateCircuit <*> ,((0 -tuples_on BOOLEAN ) --> FALSE );
set h0 = [<*> ,((0 -tuples_on BOOLEAN ) --> FALSE )];
let n be Nat; :: thesis: for x, y being FinSequence holds
( (n + 1) -BitGFA0Str x,y = (n -BitGFA0Str x,y) +* (BitGFA0Str (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0Circ x,y = (n -BitGFA0Circ x,y) +* (BitGFA0Circ (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0CarryOutput x,y = GFA0CarryOutput (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y) )

let x, y be FinSequence; :: thesis: ( (n + 1) -BitGFA0Str x,y = (n -BitGFA0Str x,y) +* (BitGFA0Str (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0Circ x,y = (n -BitGFA0Circ x,y) +* (BitGFA0Circ (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0CarryOutput x,y = GFA0CarryOutput (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y) )
consider f, g, h being ManySortedSet of NAT such that
A1: n -BitGFA0Str x,y = f . n and
A2: n -BitGFA0Circ x,y = g . n and
A3: f . 0 = 1GateCircStr <*> ,((0 -tuples_on BOOLEAN ) --> FALSE ) and
A4: g . 0 = 1GateCircuit <*> ,((0 -tuples_on BOOLEAN ) --> FALSE ) and
A5: h . 0 = [<*> ,((0 -tuples_on BOOLEAN ) --> FALSE )] 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 +* (BitGFA0Str (x . (n + 1)),(y . (n + 1)),z) & g . (n + 1) = A +* (BitGFA0Circ (x . (n + 1)),(y . (n + 1)),z) & h . (n + 1) = GFA0CarryOutput (x . (n + 1)),(y . (n + 1)),z ) by Def2;
A7: n -BitGFA0CarryOutput x,y = h . n by A3, A4, A5, A6, Th1;
A8: (n + 1) -BitGFA0Str x,y = f . (n + 1) by A3, A4, A5, A6, Th1;
A9: (n + 1) -BitGFA0Circ x,y = g . (n + 1) by A3, A4, A5, A6, Th1;
(n + 1) -BitGFA0CarryOutput x,y = h . (n + 1) by A3, A4, A5, A6, Th1;
hence ( (n + 1) -BitGFA0Str x,y = (n -BitGFA0Str x,y) +* (BitGFA0Str (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0Circ x,y = (n -BitGFA0Circ x,y) +* (BitGFA0Circ (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y)) & (n + 1) -BitGFA0CarryOutput x,y = GFA0CarryOutput (x . (n + 1)),(y . (n + 1)),(n -BitGFA0CarryOutput x,y) ) by A1, A2, A6, A7, A8, A9; :: thesis: verum