let s, a, b be Ordinal; :: thesis: ( ex C being Cantor-normal-form Ordinal-Sequence st
( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF a))) \/ (rng (omega -exponent (CantorNF b))) & ( for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) /\ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) ) ) ) ) implies ex C being Cantor-normal-form Ordinal-Sequence st
( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF b))) \/ (rng (omega -exponent (CantorNF a))) & ( for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) /\ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) ) ) ) ) )

set E1 = omega -exponent (CantorNF a);
set E2 = omega -exponent (CantorNF b);
set L1 = omega -leading_coeff (CantorNF a);
set L2 = omega -leading_coeff (CantorNF b);
given C being Cantor-normal-form Ordinal-Sequence such that A48: ( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF a))) \/ (rng (omega -exponent (CantorNF b))) ) and
A49: for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) /\ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) ) ) ; :: thesis: ex C being Cantor-normal-form Ordinal-Sequence st
( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF b))) \/ (rng (omega -exponent (CantorNF a))) & ( for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) /\ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) ) ) ) )

take C ; :: thesis: ( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF b))) \/ (rng (omega -exponent (CantorNF a))) & ( for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) /\ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) ) ) ) )

thus ( s = Sum^ C & rng (omega -exponent C) = (rng (omega -exponent (CantorNF b))) \/ (rng (omega -exponent (CantorNF a))) ) by A48; :: thesis: for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) /\ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) ) )

thus for d being object st d in dom C holds
( ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) \ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF a))) \ (rng (omega -exponent (CantorNF b))) implies omega -leading_coeff (C . d) = (omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d))) ) & ( omega -exponent (C . d) in (rng (omega -exponent (CantorNF b))) /\ (rng (omega -exponent (CantorNF a))) implies omega -leading_coeff (C . d) = ((omega -leading_coeff (CantorNF b)) . (((omega -exponent (CantorNF b)) ") . (omega -exponent (C . d)))) + ((omega -leading_coeff (CantorNF a)) . (((omega -exponent (CantorNF a)) ") . (omega -exponent (C . d)))) ) ) by A49; :: thesis: verum