let f be FinSequence of (TOP-REAL 2); for p being Point of (TOP-REAL 2)
for i being Element of NAT st p in LSeg f,i holds
Index p,f <= i
let p be Point of (TOP-REAL 2); for i being Element of NAT st p in LSeg f,i holds
Index p,f <= i
let i0 be Element of NAT ; ( p in LSeg f,i0 implies Index p,f <= i0 )
assume A1:
p in LSeg f,i0
; Index p,f <= i0
LSeg f,i0 c= L~ f
by TOPREAL3:26;
then consider S being non empty Subset of NAT such that
A2:
Index p,f = min S
and
A3:
S = { i where i is Element of NAT : p in LSeg f,i }
by A1, Def2;
i0 in S
by A1, A3;
hence
Index p,f <= i0
by A2, XXREAL_2:def 7; verum