let f be FinSequence of (TOP-REAL 2); :: thesis: for p being Point of (TOP-REAL 2) st p in L~ f holds
( 1 <= Index p,f & Index p,f < len f )
let p be Point of (TOP-REAL 2); :: thesis: ( p in L~ f implies ( 1 <= Index p,f & Index p,f < len f ) )
assume
p in L~ f
; :: thesis: ( 1 <= Index p,f & Index p,f < len f )
then consider S being non empty Subset of NAT such that
A1:
Index p,f = min S
and
A2:
S = { i where i is Element of NAT : p in LSeg f,i }
by Def2;
Index p,f in S
by A1, XXREAL_2:def 7;
then A3:
ex i being Element of NAT st
( i = Index p,f & p in LSeg f,i )
by A2;
hence
1 <= Index p,f
by TOPREAL1:def 5; :: thesis: Index p,f < len f
(Index p,f) + 1 <= len f
by A3, TOPREAL1:def 5;
hence
Index p,f < len f
by NAT_1:13; :: thesis: verum