let F be FinSequence of INT ; for m being Nat st 1 <= m & m <= len F holds
min_at (F,m,m) = m
let m be Nat; ( 1 <= m & m <= len F implies min_at (F,m,m) = m )
assume that
A1:
1 <= m
and
A2:
m <= len F
; min_at (F,m,m) = m
A3:
for i being Nat st m <= i & i < m holds
F . m < F . i
;
for i being Nat st m <= i & i <= m holds
F . m <= F . i
by XXREAL_0:1;
hence
min_at (F,m,m) = m
by A1, A2, A3, Th59; verum