let r be Real; BHSP_3:def 1 ( r > 0 implies ex k being Nat st
for n, m being Nat st n >= k & m >= k holds
dist (((seq + x) . n),((seq + x) . m)) < r )
assume
r > 0
; ex k being Nat st
for n, m being Nat st n >= k & m >= k holds
dist (((seq + x) . n),((seq + x) . m)) < r
then consider m1 being Nat such that
A1:
for n, m being Nat st n >= m1 & m >= m1 holds
dist ((seq . n),(seq . m)) < r
by Def1;
take k = m1; for n, m being Nat st n >= k & m >= k holds
dist (((seq + x) . n),((seq + x) . m)) < r
let n, m be Nat; ( n >= k & m >= k implies dist (((seq + x) . n),((seq + x) . m)) < r )
dist (((seq . n) + x),((seq . m) + x)) <= (dist ((seq . n),(seq . m))) + (dist (x,x))
by BHSP_1:40;
then A2:
dist (((seq . n) + x),((seq . m) + x)) <= (dist ((seq . n),(seq . m))) + 0
by BHSP_1:34;
assume
( n >= k & m >= k )
; dist (((seq + x) . n),((seq + x) . m)) < r
then
dist ((seq . n),(seq . m)) < r
by A1;
then
dist (((seq . n) + x),((seq . m) + x)) < r
by A2, XXREAL_0:2;
then
dist (((seq + x) . n),((seq . m) + x)) < r
by BHSP_1:def 6;
hence
dist (((seq + x) . n),((seq + x) . m)) < r
by BHSP_1:def 6; verum