theorem Th1:
for
i1 being
Nat st 1
<= i1 holds
i1 -' 1
< i1
theorem
for
i,
k being
Nat st
i + 1
<= k holds
1
<= k -' i
theorem
for
i,
k being
Nat st 1
<= i & 1
<= k holds
(k -' i) + 1
<= k
Lm1:
for r being Real st 0 <= r & r <= 1 holds
( 0 <= 1 - r & 1 - r <= 1 )
reconsider jj = 1 as Real ;
theorem
for
p1,
p2,
q1,
q2,
q3 being
Point of
(TOP-REAL 2) st
p1 <> p2 &
LE q1,
q2,
p1,
p2 &
LE q2,
q3,
p1,
p2 holds
LE q1,
q3,
p1,
p2
Lm2:
for f being FinSequence of (TOP-REAL 2)
for p, q being Point of (TOP-REAL 2) st p in L~ f & q in L~ f & p <> f . (len f) & f is being_S-Seq & not p in L~ (L_Cut (f,q)) holds
q in L~ (L_Cut (f,p))
Lm3:
for f being FinSequence of (TOP-REAL 2)
for p, q being Point of (TOP-REAL 2) st p in L~ f & q in L~ f & ( Index (p,f) < Index (q,f) or ( Index (p,f) = Index (q,f) & LE p,q,f /. (Index (p,f)),f /. ((Index (p,f)) + 1) ) ) & p <> q holds
L~ (B_Cut (f,p,q)) c= L~ f
theorem
for
f being
FinSequence of
(TOP-REAL 2) for
p,
q being
Point of
(TOP-REAL 2) st
p in L~ f &
q in L~ f & (
Index (
p,
f)
< Index (
q,
f) or (
Index (
p,
f)
= Index (
q,
f) &
LE p,
q,
f /. (Index (p,f)),
f /. ((Index (p,f)) + 1) ) ) &
p <> q holds
L~ (B_Cut (f,p,q)) c= L~ f by Lm3;