let X be RealUnitarySpace; for seq1, seq2 being sequence of X
for k being Nat st seq1 is_compared_to seq2 holds
seq1 ^\ k is_compared_to seq2 ^\ k
let seq1, seq2 be sequence of X; for k being Nat st seq1 is_compared_to seq2 holds
seq1 ^\ k is_compared_to seq2 ^\ k
let k be Nat; ( seq1 is_compared_to seq2 implies seq1 ^\ k is_compared_to seq2 ^\ k )
assume A1:
seq1 is_compared_to seq2
; seq1 ^\ k is_compared_to seq2 ^\ k
let r be Real; BHSP_3:def 2 ( r > 0 implies ex m being Nat st
for n being Nat st n >= m holds
dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r )
assume
r > 0
; ex m being Nat st
for n being Nat st n >= m holds
dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r
then consider m1 being Nat such that
A2:
for n being Nat st n >= m1 holds
dist ((seq1 . n),(seq2 . n)) < r
by A1;
take m = m1; for n being Nat st n >= m holds
dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r
let n be Nat; ( n >= m implies dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r )
assume A3:
n >= m
; dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r
n + k >= n
by NAT_1:11;
then
n + k >= m
by A3, XXREAL_0:2;
then
dist ((seq1 . (n + k)),(seq2 . (n + k))) < r
by A2;
then
dist (((seq1 ^\ k) . n),(seq2 . (n + k))) < r
by NAT_1:def 3;
hence
dist (((seq1 ^\ k) . n),((seq2 ^\ k) . n)) < r
by NAT_1:def 3; verum