:: SPPOL_1 semantic presentation  Show TPTP formulae Show IDV graph for whole article:: Showing IDV graph ... (Click the Palm Trees again to close it)

theorem :: SPPOL_1:1  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:2  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:3  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:4  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:5  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for r, s being real number st r <= s holds
( r - 1 <= s & r - 1 < s & r <= s + 1 & r < s + 1 ) by XREAL_1:147, XREAL_1:149;

theorem :: SPPOL_1:6  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n, k being Nat st n < k holds
n <= k - 1
proof end;

theorem :: SPPOL_1:7  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for k, m, n being Nat st 1 <= k - m & k - m <= n holds
( k - m in Seg n & k - m is Nat )
proof end;

Lm1: for r1, r2, s1, s2 being real number st r1 >= 0 & r2 >= 0 & s1 >= 0 & s2 >= 0 & (r1 * s1) + (r2 * s2) = 0 holds
( ( r1 = 0 or s1 = 0 ) & ( r2 = 0 or s2 = 0 ) )
by XREAL_1:73;

theorem :: SPPOL_1:8  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:9  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:10  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: SPPOL_1:11  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem Th12: :: SPPOL_1:12  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for r, s1, s2 being real number st 0 <= r & r <= 1 & s1 >= 0 & s2 >= 0 & (r * s1) + ((1 - r) * s2) = 0 & not ( r = 0 & s2 = 0 ) & not ( r = 1 & s1 = 0 ) holds
( s1 = 0 & s2 = 0 )
proof end;

theorem Th13: :: SPPOL_1:13  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for r, r1, r2 being real number st r < r1 & r < r2 holds
r < min r1,r2
proof end;

theorem Th14: :: SPPOL_1:14  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for r, r1, r2 being real number st r > r1 & r > r2 holds
r > max r1,r2
proof end;

scheme :: SPPOL_1:sch 1
FinSeqFam{ F1() -> non empty set , F2() -> FinSequence of F1(), F3( FinSequence of F1(), Nat) -> set , P1[ Nat] } :
{ F3(F2(),i) where i is Nat : ( i in dom F2() & P1[i] ) } is finite
proof end;

scheme :: SPPOL_1:sch 2
FinSeqFam'{ F1() -> non empty set , F2() -> FinSequence of F1(), F3( FinSequence of F1(), Nat) -> set , P1[ Nat] } :
{ F3(F2(),i) where i is Nat : ( 1 <= i & i <= len F2() & P1[i] ) } is finite
proof end;

theorem Th15: :: SPPOL_1:15  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for x1, x2, x3 being Element of REAL n holds |.(x1 - x2).| - |.(x2 - x3).| <= |.(x1 - x3).|
proof end;

theorem :: SPPOL_1:16  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for x1, x2, x3 being Element of REAL n holds |.(x2 - x1).| - |.(x2 - x3).| <= |.(x3 - x1).|
proof end;

theorem Th17: :: SPPOL_1:17  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p being Point of (TOP-REAL n) holds
( p is Element of REAL n & p is Point of (Euclid n) ) by EUCLID:25;

theorem :: SPPOL_1:18  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for up being Point of (Euclid n) holds
( up is Element of REAL n & up is Point of (TOP-REAL n) ) by EUCLID:25;

theorem :: SPPOL_1:19  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for x being Element of REAL n holds
( x is Point of (Euclid n) & x is Point of (TOP-REAL n) ) by EUCLID:25;

theorem Th20: :: SPPOL_1:20  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for u1, u2 being Point of (Euclid n)
for v1, v2 being Element of REAL n st v1 = u1 & v2 = u2 holds
dist u1,u2 = |.(v1 - v2).|
proof end;

theorem Th21: :: SPPOL_1:21  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p, p1, p2 being Point of (TOP-REAL n) st p in LSeg p1,p2 holds
ex r being Real st
( 0 <= r & r <= 1 & p = ((1 - r) * p1) + (r * p2) )
proof end;

theorem :: SPPOL_1:22  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2 being Point of (TOP-REAL n)
for r being Real st 0 <= r & r <= 1 holds
((1 - r) * p1) + (r * p2) in LSeg p1,p2 ;

theorem :: SPPOL_1:23  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2 being Point of (TOP-REAL n)
for P being non empty Subset of (TOP-REAL n) st P is closed & P c= LSeg p1,p2 holds
ex s being Real st
( ((1 - s) * p1) + (s * p2) in P & ( for r being Real st 0 <= r & r <= 1 & ((1 - r) * p1) + (r * p2) in P holds
s <= r ) )
proof end;

theorem Th24: :: SPPOL_1:24  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2, q1, q2 being Point of (TOP-REAL n) st LSeg q1,q2 c= LSeg p1,p2 & p1 in LSeg q1,q2 & not p1 = q1 holds
p1 = q2
proof end;

theorem :: SPPOL_1:25  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2, q1, q2 being Point of (TOP-REAL n) holds
( not LSeg p1,p2 = LSeg q1,q2 or ( p1 = q1 & p2 = q2 ) or ( p1 = q2 & p2 = q1 ) )
proof end;

theorem :: SPPOL_1:26  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat holds TOP-REAL n is_T2 ;

theorem :: SPPOL_1:27  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p being Point of (TOP-REAL n) holds {p} is closed by PCOMPS_1:10;

theorem Th28: :: SPPOL_1:28  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2 being Point of (TOP-REAL n) holds LSeg p1,p2 is compact
proof end;

theorem Th29: :: SPPOL_1:29  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2 being Point of (TOP-REAL n) holds LSeg p1,p2 is closed
proof end;

definition
let n be Nat;
let p be Point of (TOP-REAL n);
let P be Subset of (TOP-REAL n);
pred p is_extremal_in P means :Def1: :: SPPOL_1:def 1
( p in P & ( for p1, p2 being Point of (TOP-REAL n) st p in LSeg p1,p2 & LSeg p1,p2 c= P & not p = p1 holds
p = p2 ) );
end;

:: deftheorem Def1 defines is_extremal_in SPPOL_1:def 1 :
for n being Nat
for p being Point of (TOP-REAL n)
for P being Subset of (TOP-REAL n) holds
( p is_extremal_in P iff ( p in P & ( for p1, p2 being Point of (TOP-REAL n) st p in LSeg p1,p2 & LSeg p1,p2 c= P & not p = p1 holds
p = p2 ) ) );

theorem :: SPPOL_1:30  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p being Point of (TOP-REAL n)
for P, Q being Subset of (TOP-REAL n) st p is_extremal_in P & Q c= P & p in Q holds
p is_extremal_in Q
proof end;

theorem :: SPPOL_1:31  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p being Point of (TOP-REAL n) holds p is_extremal_in {p}
proof end;

theorem Th32: :: SPPOL_1:32  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p1, p2 being Point of (TOP-REAL n) holds p1 is_extremal_in LSeg p1,p2
proof end;

theorem :: SPPOL_1:33  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p2, p1 being Point of (TOP-REAL n) holds p2 is_extremal_in LSeg p1,p2 by Th32;

theorem :: SPPOL_1:34  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for n being Nat
for p, p1, p2 being Point of (TOP-REAL n) holds
( not p is_extremal_in LSeg p1,p2 or p = p1 or p = p2 )
proof end;

theorem Th35: :: SPPOL_1:35  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for p1, p2 being Point of (TOP-REAL 2) st p1 `1 <> p2 `1 & p1 `2 <> p2 `2 holds
ex p being Point of (TOP-REAL 2) st
( p in LSeg p1,p2 & p `1 <> p1 `1 & p `1 <> p2 `1 & p `2 <> p1 `2 & p `2 <> p2 `2 )
proof end;

definition
let P be Subset of (TOP-REAL 2);
attr P is horizontal means :Def2: :: SPPOL_1:def 2
for p, q being Point of (TOP-REAL 2) st p in P & q in P holds
p `2 = q `2 ;
attr P is vertical means :Def3: :: SPPOL_1:def 3
for p, q being Point of (TOP-REAL 2) st p in P & q in P holds
p `1 = q `1 ;
end;

:: deftheorem Def2 defines horizontal SPPOL_1:def 2 :
for P being Subset of (TOP-REAL 2) holds
( P is horizontal iff for p, q being Point of (TOP-REAL 2) st p in P & q in P holds
p `2 = q `2 );

:: deftheorem Def3 defines vertical SPPOL_1:def 3 :
for P being Subset of (TOP-REAL 2) holds
( P is vertical iff for p, q being Point of (TOP-REAL 2) st p in P & q in P holds
p `1 = q `1 );

Lm2: for P being Subset of (TOP-REAL 2) st not P is trivial & P is horizontal holds
not P is vertical
proof end;

registration
cluster non trivial horizontal -> non vertical Element of K40(the carrier of (TOP-REAL 2));
coherence
for b1 being Subset of (TOP-REAL 2) st not b1 is trivial & b1 is horizontal holds
not b1 is vertical
by Lm2;
cluster non trivial vertical -> non horizontal Element of K40(the carrier of (TOP-REAL 2));
coherence
for b1 being Subset of (TOP-REAL 2) st not b1 is trivial & b1 is vertical holds
not b1 is horizontal
by Lm2;
end;

theorem Th36: :: SPPOL_1:36  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for p, q being Point of (TOP-REAL 2) holds
( p `2 = q `2 iff LSeg p,q is horizontal )
proof end;

theorem Th37: :: SPPOL_1:37  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for p, q being Point of (TOP-REAL 2) holds
( p `1 = q `1 iff LSeg p,q is vertical )
proof end;

theorem :: SPPOL_1:38  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for p1, p, q, p2 being Point of (TOP-REAL 2) st p1 in LSeg p,q & p2 in LSeg p,q & p1 `1 <> p2 `1 & p1 `2 = p2 `2 holds
LSeg p,q is horizontal
proof end;

theorem :: SPPOL_1:39  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for p1, p, q, p2 being Point of (TOP-REAL 2) st p1 in LSeg p,q & p2 in LSeg p,q & p1 `2 <> p2 `2 & p1 `1 = p2 `1 holds
LSeg p,q is vertical
proof end;

theorem Th40: :: SPPOL_1:40  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) holds LSeg f,i is closed
proof end;

theorem Th41: :: SPPOL_1:41  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) holds
( not f is special or LSeg f,i is vertical or LSeg f,i is horizontal )
proof end;

theorem Th42: :: SPPOL_1:42  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is one-to-one & 1 <= i & i + 1 <= len f holds
not LSeg f,i is trivial
proof end;

theorem :: SPPOL_1:43  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is one-to-one & 1 <= i & i + 1 <= len f & LSeg f,i is vertical holds
not LSeg f,i is horizontal
proof end;

theorem Th44: :: SPPOL_1:44  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for f being FinSequence of the carrier of (TOP-REAL 2) holds { (LSeg f,i) where i is Nat : ( 1 <= i & i <= len f ) } is finite
proof end;

theorem Th45: :: SPPOL_1:45  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for f being FinSequence of the carrier of (TOP-REAL 2) holds { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f ) } is finite
proof end;

Lm3: for f being FinSequence of the carrier of (TOP-REAL 2)
for k being Nat holds { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f & i <> k & i <> k + 1 ) } is finite
proof end;

theorem :: SPPOL_1:46  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for f being FinSequence of the carrier of (TOP-REAL 2) holds { (LSeg f,i) where i is Nat : ( 1 <= i & i <= len f ) } is Subset-Family of (TOP-REAL 2)
proof end;

theorem Th47: :: SPPOL_1:47  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for f being FinSequence of the carrier of (TOP-REAL 2) holds { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f ) } is Subset-Family of (TOP-REAL 2)
proof end;

Lm4: for f being FinSequence of the carrier of (TOP-REAL 2)
for k being Nat holds { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f & i <> k & i <> k + 1 ) } is Subset-Family of (TOP-REAL 2)
proof end;

theorem Th48: :: SPPOL_1:48  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for Q being Subset of (TOP-REAL 2)
for f being FinSequence of the carrier of (TOP-REAL 2) st Q = union { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f ) } holds
Q is closed
proof end;

theorem :: SPPOL_1:49  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for f being FinSequence of the carrier of (TOP-REAL 2) holds L~ f is closed by Th48;

Lm5: for f being FinSequence of the carrier of (TOP-REAL 2)
for Q being Subset of (TOP-REAL 2)
for k being Nat st Q = union { (LSeg f,i) where i is Nat : ( 1 <= i & i + 1 <= len f & i <> k & i <> k + 1 ) } holds
Q is closed
proof end;

definition
let IT be FinSequence of (TOP-REAL 2);
attr IT is alternating means :Def4: :: SPPOL_1:def 4
for i being Nat st 1 <= i & i + 2 <= len IT holds
( (IT /. i) `1 <> (IT /. (i + 2)) `1 & (IT /. i) `2 <> (IT /. (i + 2)) `2 );
end;

:: deftheorem Def4 defines alternating SPPOL_1:def 4 :
for IT being FinSequence of (TOP-REAL 2) holds
( IT is alternating iff for i being Nat st 1 <= i & i + 2 <= len IT holds
( (IT /. i) `1 <> (IT /. (i + 2)) `1 & (IT /. i) `2 <> (IT /. (i + 2)) `2 ) );

theorem Th50: :: SPPOL_1:50  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & (f /. i) `1 = (f /. (i + 1)) `1 holds
(f /. (i + 1)) `2 = (f /. (i + 2)) `2
proof end;

theorem Th51: :: SPPOL_1:51  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & (f /. i) `2 = (f /. (i + 1)) `2 holds
(f /. (i + 1)) `1 = (f /. (i + 2)) `1
proof end;

theorem Th52: :: SPPOL_1:52  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2)
for p1, p2, p3 being Point of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & p1 = f /. i & p2 = f /. (i + 1) & p3 = f /. (i + 2) & not ( p1 `1 = p2 `1 & p3 `1 <> p2 `1 ) holds
( p1 `2 = p2 `2 & p3 `2 <> p2 `2 )
proof end;

theorem :: SPPOL_1:53  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2)
for p1, p2, p3 being Point of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & p1 = f /. i & p2 = f /. (i + 1) & p3 = f /. (i + 2) & not ( p2 `1 = p3 `1 & p1 `1 <> p2 `1 ) holds
( p2 `2 = p3 `2 & p1 `2 <> p2 `2 )
proof end;

Lm6: for f being FinSequence of the carrier of (TOP-REAL 2)
for i being Nat
for p1, p2 being Point of (TOP-REAL 2) st f is alternating & 1 <= i & i + 2 <= len f & p1 = f /. i & p2 = f /. (i + 2) holds
ex p being Point of (TOP-REAL 2) st
( p in LSeg p1,p2 & p `1 <> p1 `1 & p `1 <> p2 `1 & p `2 <> p1 `2 & p `2 <> p2 `2 )
proof end;

theorem :: SPPOL_1:54  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f holds
not LSeg (f /. i),(f /. (i + 2)) c= (LSeg f,i) \/ (LSeg f,(i + 1))
proof end;

theorem Th55: :: SPPOL_1:55  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & LSeg f,i is vertical holds
LSeg f,(i + 1) is horizontal
proof end;

theorem Th56: :: SPPOL_1:56  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & LSeg f,i is horizontal holds
LSeg f,(i + 1) is vertical
proof end;

theorem :: SPPOL_1:57  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & not ( LSeg f,i is vertical & LSeg f,(i + 1) is horizontal ) holds
( LSeg f,i is horizontal & LSeg f,(i + 1) is vertical )
proof end;

theorem Th58: :: SPPOL_1:58  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2)
for p, q being Point of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & f /. (i + 1) in LSeg p,q & LSeg p,q c= (LSeg f,i) \/ (LSeg f,(i + 1)) & not f /. (i + 1) = p holds
f /. (i + 1) = q
proof end;

theorem Th59: :: SPPOL_1:59  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f holds
f /. (i + 1) is_extremal_in (LSeg f,i) \/ (LSeg f,(i + 1))
proof end;

theorem Th60: :: SPPOL_1:60  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for f being FinSequence of the carrier of (TOP-REAL 2)
for p, q being Point of (TOP-REAL 2)
for u being Point of (Euclid 2) st f is special & f is alternating & 1 <= i & i + 2 <= len f & u = f /. (i + 1) & f /. (i + 1) in LSeg p,q & f /. (i + 1) <> q & not p in (LSeg f,i) \/ (LSeg f,(i + 1)) holds
for s being Real st s > 0 holds
ex p3 being Point of (TOP-REAL 2) st
( not p3 in (LSeg f,i) \/ (LSeg f,(i + 1)) & p3 in LSeg p,q & p3 in Ball u,s )
proof end;

definition
let f1, f2 be FinSequence of the carrier of (TOP-REAL 2);
let P be Subset of (TOP-REAL 2);
pred f1,f2 are_generators_of P means :Def5: :: SPPOL_1:def 5
( f1 is alternating & f1 is being_S-Seq & f2 is alternating & f2 is being_S-Seq & f1 /. 1 = f2 /. 1 & f1 /. (len f1) = f2 /. (len f2) & <*(f1 /. 2),(f1 /. 1),(f2 /. 2)*> is alternating & <*(f1 /. ((len f1) - 1)),(f1 /. (len f1)),(f2 /. ((len f2) - 1))*> is alternating & f1 /. 1 <> f1 /. (len f1) & (L~ f1) /\ (L~ f2) = {(f1 /. 1),(f1 /. (len f1))} & P = (L~ f1) \/ (L~ f2) );
end;

:: deftheorem Def5 defines are_generators_of SPPOL_1:def 5 :
for f1, f2 being FinSequence of the carrier of (TOP-REAL 2)
for P being Subset of (TOP-REAL 2) holds
( f1,f2 are_generators_of P iff ( f1 is alternating & f1 is being_S-Seq & f2 is alternating & f2 is being_S-Seq & f1 /. 1 = f2 /. 1 & f1 /. (len f1) = f2 /. (len f2) & <*(f1 /. 2),(f1 /. 1),(f2 /. 2)*> is alternating & <*(f1 /. ((len f1) - 1)),(f1 /. (len f1)),(f2 /. ((len f2) - 1))*> is alternating & f1 /. 1 <> f1 /. (len f1) & (L~ f1) /\ (L~ f2) = {(f1 /. 1),(f1 /. (len f1))} & P = (L~ f1) \/ (L~ f2) ) );

theorem :: SPPOL_1:61  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for i being Nat
for P being Subset of (TOP-REAL 2)
for f1, f2 being FinSequence of the carrier of (TOP-REAL 2) st f1,f2 are_generators_of P & 1 < i & i < len f1 holds
f1 /. i is_extremal_in P
proof end;