let S, T be RealNormSpace; for i being Nat holds diff_SP ((i + 1),S,T) = R_NormSpace_of_BoundedLinearOperators (S,(diff_SP (i,S,T)))
let i be Nat; diff_SP ((i + 1),S,T) = R_NormSpace_of_BoundedLinearOperators (S,(diff_SP (i,S,T)))
set H = diff_SP (i,S,T);
ex H1 being RealNormSpace st
( H1 = (diff_SP (S,T)) . i & (diff_SP (S,T)) . (i + 1) = R_NormSpace_of_BoundedLinearOperators (S,H1) )
by Th9;
hence
diff_SP ((i + 1),S,T) = R_NormSpace_of_BoundedLinearOperators (S,(diff_SP (i,S,T)))
; verum