let p1, p2 be Point of (TOP-REAL 2); :: thesis: ( p1 <> p2 & p2 in R^2-unit_square & p1 in LSeg |[0 ,0 ]|,|[1,0 ]| implies ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} ) )

assume that
A1: p1 <> p2 and
A2: p2 in R^2-unit_square and
A3: p1 in LSeg |[0 ,0 ]|,|[1,0 ]| ; :: thesis: ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

A4: ( p2 in (LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|) or p2 in (LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|) ) by A2, TOPREAL1:def 4, XBOOLE_0:def 3;
consider p being Point of (TOP-REAL 2) such that
A5: p = p1 and
A6: ( p `1 <= 1 & p `1 >= 0 & p `2 = 0 ) by A3, TOPREAL1:19;
A7: LSeg |[0 ,0 ]|,p1 c= LSeg |[0 ,0 ]|,|[1,0 ]| by A3, Lm14, TOPREAL1:12;
A8: LSeg |[1,0 ]|,p1 c= LSeg |[0 ,0 ]|,|[1,0 ]| by A3, Lm17, TOPREAL1:12;
then ( (LSeg |[1,0 ]|,p1) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A9: (LSeg |[1,0 ]|,p1) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
|[1,0 ]| in LSeg |[1,0 ]|,p1 by RLTOPSP1:69;
then A10: ( (LSeg |[1,0 ]|,p1) /\ (LSeg |[1,0 ]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) & (LSeg |[1,0 ]|,p1) /\ (LSeg |[1,0 ]|,|[1,1]|) <> {} ) by A8, Lm18, XBOOLE_0:def 4, XBOOLE_1:26;
|[0 ,0 ]| in LSeg p1,|[0 ,0 ]| by RLTOPSP1:69;
then A11: ( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) & |[0 ,0 ]| in (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) ) by A7, Lm13, XBOOLE_0:def 4, XBOOLE_1:26;
A12: (LSeg p1,|[0 ,0 ]|) /\ (LSeg p1,|[1,0 ]|) = {p1} by A3, TOPREAL1:14;
( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A7, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A13: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
per cases ( p2 in LSeg |[0 ,0 ]|,|[0 ,1]| or p2 in LSeg |[0 ,1]|,|[1,1]| or p2 in LSeg |[0 ,0 ]|,|[1,0 ]| or p2 in LSeg |[1,0 ]|,|[1,1]| ) by A4, XBOOLE_0:def 3;
suppose A14: p2 in LSeg |[0 ,0 ]|,|[0 ,1]| ; :: thesis: ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

then A15: ex q being Point of (TOP-REAL 2) st
( q = p2 & q `1 = 0 & q `2 <= 1 & q `2 >= 0 ) by TOPREAL1:19;
A16: LSeg |[0 ,0 ]|,p2 c= LSeg |[0 ,0 ]|,|[0 ,1]| by A14, Lm13, TOPREAL1:12;
A17: LSeg p2,|[0 ,1]| c= LSeg |[0 ,0 ]|,|[0 ,1]| by A14, Lm15, TOPREAL1:12;
take P1 = (LSeg p1,|[0 ,0 ]|) \/ (LSeg |[0 ,0 ]|,p2); :: thesis: ex P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

take P2 = (LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)); :: thesis: ( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
( |[0 ,0 ]| in LSeg p1,|[0 ,0 ]| & |[0 ,0 ]| in LSeg |[0 ,0 ]|,p2 ) by RLTOPSP1:69;
then ( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,p2) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) & |[0 ,0 ]| in (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,p2) & (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) = {|[0 ,0 ]|} ) by A7, A16, TOPREAL1:23, XBOOLE_0:def 4, XBOOLE_1:27;
then ( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,p2) = {|[0 ,0 ]|} & ( p1 <> |[0 ,0 ]| or |[0 ,0 ]| <> p2 ) ) by A1, ZFMISC_1:39;
hence P1 is_an_arc_of p1,p2 by TOPREAL1:18; :: thesis: ( P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
( LSeg |[1,0 ]|,|[1,1]| is_an_arc_of |[1,0 ]|,|[1,1]| & LSeg |[0 ,1]|,|[1,1]| is_an_arc_of |[1,1]|,|[0 ,1]| ) by Lm4, TOPREAL1:15;
then A18: (LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|) is_an_arc_of |[1,0 ]|,|[0 ,1]| by TOPREAL1:5, TOPREAL1:24;
A19: (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,1]|,p2) = {} by A17, Lm3, XBOOLE_1:3, XBOOLE_1:26;
|[0 ,1]| in LSeg |[0 ,1]|,p2 by RLTOPSP1:69;
then A20: ( (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,1]|,p2) c= (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) & |[0 ,1]| in (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,1]|,p2) ) by A17, Lm16, XBOOLE_0:def 4, XBOOLE_1:27;
((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[0 ,1]|,p2) = ((LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,1]|,p2)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,1]|,p2)) by XBOOLE_1:23
.= {|[0 ,1]|} by A19, A20, TOPREAL1:21, ZFMISC_1:39 ;
then A21: ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2) is_an_arc_of |[1,0 ]|,p2 by A18, TOPREAL1:16;
A22: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,p2) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A8, A17, XBOOLE_1:27;
now
assume |[0 ,0 ]| in (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,p2) ; :: thesis: contradiction
then ( |[0 ,0 ]| in LSeg p1,|[1,0 ]| & |[0 ,0 ]| in LSeg p2,|[0 ,1]| & p1 `1 <= |[1,0 ]| `1 & p2 `2 <= |[0 ,1]| `2 ) by A5, A6, A15, EUCLID:56, XBOOLE_0:def 4;
then A23: ( 0 = p1 `2 & 0 = p2 `2 & 0 = p1 `1 & 0 = p2 `1 ) by A5, A6, A15, Lm4, TOPREAL1:9, TOPREAL1:10;
then p1 = |[0 ,0 ]| by EUCLID:57
.= p2 by A23, EUCLID:57 ;
hence contradiction by A1; :: thesis: verum
end;
then {|[0 ,0 ]|} <> (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,p2) by ZFMISC_1:37;
then A24: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,p2) = {} by A22, TOPREAL1:23, ZFMISC_1:39;
(LSeg p1,|[1,0 ]|) /\ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)) = ((LSeg p1,|[1,0 ]|) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,p2)) by XBOOLE_1:23
.= ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg |[1,0 ]|,p1) /\ (LSeg |[0 ,1]|,|[1,1]|)) by A24, XBOOLE_1:23
.= {|[1,0 ]|} by A9, A10, TOPREAL1:22, ZFMISC_1:39 ;
hence P2 is_an_arc_of p1,p2 by A21, TOPREAL1:17; :: thesis: ( R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
A25: (LSeg p1,|[0 ,0 ]|) \/ (LSeg p1,|[1,0 ]|) = LSeg |[0 ,0 ]|,|[1,0 ]| by A3, TOPREAL1:11;
A26: (LSeg |[0 ,1]|,p2) \/ (LSeg |[0 ,0 ]|,p2) = LSeg |[0 ,0 ]|,|[0 ,1]| by A14, TOPREAL1:11;
thus P1 \/ P2 = (LSeg |[0 ,0 ]|,p2) \/ ((LSeg p1,|[0 ,0 ]|) \/ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by XBOOLE_1:4
.= (LSeg |[0 ,0 ]|,p2) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2))) by A25, XBOOLE_1:4
.= (LSeg |[0 ,0 ]|,p2) \/ (((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ (LSeg |[0 ,1]|,p2)) by XBOOLE_1:4
.= (LSeg |[0 ,0 ]|,p2) \/ ((((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)) by XBOOLE_1:4
.= (LSeg |[0 ,0 ]|,p2) \/ (((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg |[0 ,1]|,|[1,1]|) \/ (LSeg |[0 ,1]|,p2))) by XBOOLE_1:4
.= (((LSeg |[0 ,1]|,|[1,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ (LSeg |[0 ,0 ]|,p2)) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) by XBOOLE_1:4
.= R^2-unit_square by A26, TOPREAL1:def 4, XBOOLE_1:4 ; :: thesis: P1 /\ P2 = {p1,p2}
A27: {p1} = (LSeg p1,|[0 ,0 ]|) /\ (LSeg p1,|[1,0 ]|) by A3, TOPREAL1:14;
( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A7, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A28: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
A29: {p2} = (LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,p2) by A14, TOPREAL1:14;
( (LSeg |[0 ,0 ]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} ) by A16, TOPREAL1:26, XBOOLE_0:def 7, XBOOLE_1:26;
then A30: (LSeg |[0 ,0 ]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} by XBOOLE_1:3;
A31: P1 /\ P2 = ((LSeg p1,|[0 ,0 ]|) /\ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) \/ ((LSeg |[0 ,0 ]|,p2) /\ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by XBOOLE_1:23
.= (((LSeg p1,|[0 ,0 ]|) /\ (LSeg p1,|[1,0 ]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) \/ ((LSeg |[0 ,0 ]|,p2) /\ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[0 ,0 ]|) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ ((LSeg |[0 ,0 ]|,p2) /\ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by A27, XBOOLE_1:23
.= ({p1} \/ ((((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ ((LSeg |[0 ,0 ]|,p2) /\ ((LSeg p1,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|)) \/ ((LSeg |[0 ,0 ]|,p2) /\ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,1]|,p2)))) by A28, XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|)) \/ (((LSeg |[0 ,0 ]|,p2) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ {p2})) by A29, XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|)) \/ ((((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ {p2})) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|)) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})) by A30 ;
A32: now
per cases ( p1 = |[0 ,0 ]| or p1 = |[1,0 ]| or ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ) ;
suppose A33: p1 = |[0 ,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
then (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {|[0 ,0 ]|} /\ (LSeg |[1,0 ]|,|[1,1]|) by RLTOPSP1:71;
then A34: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} by Lm1, Lm5;
( p1 in LSeg |[0 ,0 ]|,p2 & p1 in LSeg p1,|[1,0 ]| ) by A33, RLTOPSP1:69;
then ( (LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|) c= {p1} & (LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|) <> {} ) by A16, A33, TOPREAL1:23, XBOOLE_0:def 4, XBOOLE_1:26;
then (LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|) = {p1} by ZFMISC_1:39;
hence P1 /\ P2 = ({p1} \/ ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by A31, A34, XBOOLE_1:4
.= (({p1} \/ {p1}) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) ;
:: thesis: verum
end;
suppose A35: p1 = |[1,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
then A36: (LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|) = (LSeg |[0 ,0 ]|,p2) /\ {|[1,0 ]|} by RLTOPSP1:71;
not |[1,0 ]| in LSeg |[0 ,0 ]|,p2 by A16, Lm4, TOPREAL1:9;
then (LSeg |[0 ,0 ]|,p2) /\ (LSeg p1,|[1,0 ]|) = {} by A36, Lm1;
hence P1 /\ P2 = (({p1} \/ {p1}) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by A31, A35, TOPREAL1:22, XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) ;
:: thesis: verum
end;
suppose A37: ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2))) \/ (((LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
end;
end;
end;
now
per cases ( p2 = |[0 ,0 ]| or p2 = |[0 ,1]| or ( p2 <> |[0 ,1]| & p2 <> |[0 ,0 ]| ) ) ;
suppose A41: p2 = |[0 ,0 ]| ; :: thesis: ( P1 /\ P2 = {p1,p2} & P1 /\ P2 = {p1,p2} )
A42: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A7, A17, XBOOLE_1:27;
|[0 ,0 ]| in LSeg p1,|[0 ,0 ]| by RLTOPSP1:69;
then (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2) <> {} by A41, Lm13, XBOOLE_0:def 4;
then A43: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2) = {p2} by A41, A42, TOPREAL1:23, ZFMISC_1:39;
(LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {|[0 ,0 ]|} /\ (LSeg |[0 ,1]|,|[1,1]|) by A41, RLTOPSP1:71;
then (LSeg |[0 ,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by Lm1, Lm6;
hence P1 /\ P2 = {p1} \/ ({p2} \/ {p2}) by A32, A43, XBOOLE_1:4
.= {p1,p2} by ENUMSET1:41 ;
:: thesis: P1 /\ P2 = {p1,p2}
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
suppose A44: p2 = |[0 ,1]| ; :: thesis: ( P1 /\ P2 = {p1,p2} & P1 /\ P2 = {p1,p2} )
end;
suppose A47: ( p2 <> |[0 ,1]| & p2 <> |[0 ,0 ]| ) ; :: thesis: ( P1 /\ P2 = {p1,p2} & P1 /\ P2 = {p1,p2} )
end;
end;
end;
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
suppose A52: p2 in LSeg |[0 ,1]|,|[1,1]| ; :: thesis: ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

then A53: ex q being Point of (TOP-REAL 2) st
( q = p2 & q `1 <= 1 & q `1 >= 0 & q `2 = 1 ) by TOPREAL1:19;
take P1 = ((LSeg p1,|[0 ,0 ]|) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,1]|,p2); :: thesis: ex P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

take P2 = ((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2); :: thesis: ( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
A54: LSeg p2,|[0 ,1]| c= LSeg |[0 ,1]|,|[1,1]| by A52, Lm16, TOPREAL1:12;
A55: LSeg p2,|[1,1]| c= LSeg |[0 ,1]|,|[1,1]| by A52, Lm19, TOPREAL1:12;
|[0 ,1]| in LSeg |[0 ,1]|,p2 by RLTOPSP1:69;
then ( (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,1]|,p2) c= {|[0 ,1]|} & (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,1]|,p2) <> {} ) by A54, Lm15, TOPREAL1:21, XBOOLE_0:def 4, XBOOLE_1:26;
then (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,1]|,p2) = {|[0 ,1]|} by ZFMISC_1:39;
then A56: (LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2) is_an_arc_of |[0 ,0 ]|,p2 by Lm4, TOPREAL1:18;
A57: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2) = {} by A7, A54, Lm2, XBOOLE_1:3, XBOOLE_1:27;
(LSeg p1,|[0 ,0 ]|) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) = ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,p2)) by XBOOLE_1:23
.= {|[0 ,0 ]|} by A11, A57, TOPREAL1:23, ZFMISC_1:39 ;
then (LSeg p1,|[0 ,0 ]|) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) is_an_arc_of p1,p2 by A56, TOPREAL1:17;
hence P1 is_an_arc_of p1,p2 by XBOOLE_1:4; :: thesis: ( P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
( (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) c= (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & |[1,1]| in LSeg |[1,1]|,p2 ) by A55, RLTOPSP1:69, XBOOLE_1:26;
then ( (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) c= {|[1,1]|} & (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) <> {} ) by Lm20, TOPREAL1:24, XBOOLE_0:def 4;
then (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) = {|[1,1]|} by ZFMISC_1:39;
then A58: (LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2) is_an_arc_of |[1,0 ]|,p2 by Lm4, TOPREAL1:18;
A59: (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2) = {} by A8, A55, Lm2, XBOOLE_1:3, XBOOLE_1:27;
(LSeg p1,|[1,0 ]|) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2)) = ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)) by XBOOLE_1:23
.= {|[1,0 ]|} by A10, A59, TOPREAL1:22, ZFMISC_1:39 ;
then (LSeg p1,|[1,0 ]|) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2)) is_an_arc_of p1,p2 by A58, TOPREAL1:17;
hence P2 is_an_arc_of p1,p2 by XBOOLE_1:4; :: thesis: ( R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
thus R^2-unit_square = ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ ((LSeg |[0 ,1]|,p2) \/ (LSeg |[1,1]|,p2))) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) by A52, TOPREAL1:11, TOPREAL1:def 4
.= (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ (LSeg |[1,1]|,p2)) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) by XBOOLE_1:4
.= ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ (((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)) by XBOOLE_1:4
.= ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2))) by XBOOLE_1:4
.= ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ (((LSeg p1,|[0 ,0 ]|) \/ (LSeg p1,|[1,0 ]|)) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2))) by A3, TOPREAL1:11
.= ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ ((LSeg p1,|[0 ,0 ]|) \/ ((LSeg p1,|[1,0 ]|) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[1,1]|,p2)))) by XBOOLE_1:4
.= ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2)) \/ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) by XBOOLE_1:4
.= ((LSeg p1,|[0 ,0 ]|) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,p2))) \/ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)) by XBOOLE_1:4
.= P1 \/ P2 by XBOOLE_1:4 ; :: thesis: P1 /\ P2 = {p1,p2}
A60: (LSeg |[0 ,1]|,p2) /\ (LSeg |[1,1]|,p2) = {p2} by A52, TOPREAL1:14;
A61: (LSeg |[0 ,1]|,p2) /\ (LSeg p1,|[1,0 ]|) = {} by A8, A54, Lm2, XBOOLE_1:3, XBOOLE_1:27;
( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A7, A55, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:27;
then A62: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) = {} by XBOOLE_1:3;
A63: P1 /\ P2 = (((LSeg p1,|[0 ,0 ]|) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) \/ ((LSeg |[0 ,1]|,p2) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) by XBOOLE_1:23
.= (((LSeg p1,|[0 ,0 ]|) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ ((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}) by A60, XBOOLE_1:23
.= (((LSeg p1,|[0 ,0 ]|) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) \/ ((((LSeg |[0 ,1]|,p2) /\ (LSeg p1,|[1,0 ]|)) \/ ((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}) by XBOOLE_1:23
.= (((LSeg p1,|[0 ,0 ]|) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A61, XBOOLE_1:23
.= ((((LSeg p1,|[0 ,0 ]|) /\ ((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:23
.= (({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A12, A62, XBOOLE_1:23
.= (({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ ((LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:23
.= (({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg p1,|[1,0 ]|)) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:23
.= (({p1} \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg p1,|[1,0 ]|)) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by Lm3 ;
A64: now
per cases ( p1 = |[0 ,0 ]| or p1 = |[1,0 ]| or ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ) ;
suppose A65: p1 = |[0 ,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})
then (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {|[0 ,0 ]|} /\ (LSeg |[1,0 ]|,|[1,1]|) by RLTOPSP1:71;
then (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} by Lm1, Lm5;
hence P1 /\ P2 = (({p1} \/ {p1}) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A63, A65, TOPREAL1:23, XBOOLE_1:4
.= ({p1} \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) ;
:: thesis: verum
end;
suppose A66: p1 = |[1,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})
then (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg p1,|[1,0 ]|) = (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ {|[1,0 ]|} by RLTOPSP1:71;
then (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg p1,|[1,0 ]|) = {} by Lm1, Lm9;
hence P1 /\ P2 = ({p1} \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A63, A66, TOPREAL1:22; :: thesis: verum
end;
suppose A67: ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})
end;
end;
end;
now
per cases ( p2 = |[0 ,1]| or p2 = |[1,1]| or ( p2 <> |[1,1]| & p2 <> |[0 ,1]| ) ) ;
suppose A71: p2 = |[0 ,1]| ; :: thesis: P1 /\ P2 = {p1,p2}
then (LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|) = {|[0 ,1]|} /\ (LSeg |[1,0 ]|,|[1,1]|) by RLTOPSP1:71;
then (LSeg |[0 ,1]|,p2) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} by Lm1, Lm8;
hence P1 /\ P2 = {p1} \/ ({p2} \/ {p2}) by A64, A71, TOPREAL1:21, XBOOLE_1:4
.= {p1,p2} by ENUMSET1:41 ;
:: thesis: verum
end;
suppose A73: ( p2 <> |[1,1]| & p2 <> |[0 ,1]| ) ; :: thesis: P1 /\ P2 = {p1,p2}
end;
end;
end;
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
suppose A77: p2 in LSeg |[0 ,0 ]|,|[1,0 ]| ; :: thesis: ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

then consider q being Point of (TOP-REAL 2) such that
A78: q = p2 and
A79: ( q `1 <= 1 & q `1 >= 0 & q `2 = 0 ) by TOPREAL1:19;
A80: ( p = |[(p `1 ),(p `2 )]| & q = |[(q `1 ),(q `2 )]| ) by EUCLID:57;
A81: LSeg p2,|[1,0 ]| c= LSeg |[0 ,0 ]|,|[1,0 ]| by A77, Lm17, TOPREAL1:12;
A82: LSeg p2,|[0 ,0 ]| c= LSeg |[0 ,0 ]|,|[1,0 ]| by A77, Lm14, TOPREAL1:12;
A83: LSeg p1,p2 c= LSeg |[0 ,0 ]|,|[1,0 ]| by A3, A77, TOPREAL1:12;
now
per cases ( p `1 < q `1 or q `1 < p `1 ) by A1, A5, A6, A78, A79, A80, XXREAL_0:1;
suppose A84: p `1 < q `1 ; :: thesis: ex P1 being Element of K21(the carrier of (TOP-REAL 2)) ex P2 being Element of K21(the carrier of (TOP-REAL 2)) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )

take P1 = LSeg p1,p2; :: thesis: ex P2 being Element of K21(the carrier of (TOP-REAL 2)) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )

take P2 = (LSeg p1,|[0 ,0 ]|) \/ ((((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,p2)); :: thesis: ( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
thus P1 is_an_arc_of p1,p2 by A1, TOPREAL1:15; :: thesis: ( P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
A85: now
assume A86: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,p2) <> {} ; :: thesis: contradiction
consider a being Element of (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,p2);
reconsider p = a as Point of (TOP-REAL 2) by A86, TARSKI:def 3;
( p in LSeg |[0 ,0 ]|,p1 & p in LSeg p2,|[1,0 ]| & |[0 ,0 ]| `1 <= p1 `1 & p2 `1 <= |[1,0 ]| `1 ) by A5, A6, A78, A79, A86, EUCLID:56, XBOOLE_0:def 4;
then ( p `1 <= p1 `1 & p2 `1 <= p `1 ) by TOPREAL1:9;
hence contradiction by A5, A78, A84, XXREAL_0:2; :: thesis: verum
end;
A87: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) c= {|[1,0 ]|} by A3, Lm14, TOPREAL1:12, TOPREAL1:22, XBOOLE_1:26;
then {|[1,0 ]|} <> (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) by ZFMISC_1:37;
then A88: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} by A87, ZFMISC_1:39;
( (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A7, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A89: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
A90: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, Lm14, TOPREAL1:12, XBOOLE_1:26;
|[0 ,0 ]| in LSeg p1,|[0 ,0 ]| by RLTOPSP1:69;
then A91: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) <> {} by Lm13, XBOOLE_0:def 4;
A92: (LSeg p1,|[0 ,0 ]|) /\ ((((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,p2)) = ((LSeg p1,|[0 ,0 ]|) /\ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,p2)) by XBOOLE_1:23
.= ((LSeg p1,|[0 ,0 ]|) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) by A85, XBOOLE_1:23
.= ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|)) by A88, XBOOLE_1:23
.= {|[0 ,0 ]|} by A89, A90, A91, TOPREAL1:23, ZFMISC_1:39 ;
A93: (LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|) is_an_arc_of |[0 ,0 ]|,|[1,1]| by Lm4, TOPREAL1:15, TOPREAL1:16, TOPREAL1:21;
((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[1,0 ]|,|[1,1]|) = ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) by XBOOLE_1:23
.= {|[1,1]|} by Lm3, TOPREAL1:24 ;
then A94: ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|) is_an_arc_of |[0 ,0 ]|,|[1,0 ]| by A93, TOPREAL1:16;
A95: (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2) c= (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) by A77, Lm17, TOPREAL1:12, XBOOLE_1:26;
|[1,0 ]| in LSeg |[1,0 ]|,p2 by RLTOPSP1:69;
then (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2) <> {} by Lm18, XBOOLE_0:def 4;
then A96: (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2) = {|[1,0 ]|} by A95, TOPREAL1:22, ZFMISC_1:39;
A97: (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,p2) c= {|[0 ,0 ]|} by A77, Lm17, TOPREAL1:12, TOPREAL1:23, XBOOLE_1:26;
then {|[0 ,0 ]|} <> (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,p2) by ZFMISC_1:37;
then A98: (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,p2) = {} by A97, ZFMISC_1:39;
( (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2) c= (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A81, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A99: (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2) = {} by XBOOLE_1:3;
(((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) /\ (LSeg |[1,0 ]|,p2) = (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[1,0 ]|,p2)) \/ ((LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2)) by XBOOLE_1:23
.= (((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,p2)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,0 ]|,p2))) \/ {|[1,0 ]|} by A96, XBOOLE_1:23
.= {|[1,0 ]|} by A98, A99 ;
then (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,p2) is_an_arc_of |[0 ,0 ]|,p2 by A94, TOPREAL1:16;
hence P2 is_an_arc_of p1,p2 by A92, TOPREAL1:17; :: thesis: ( P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
thus P1 \/ P2 = ((LSeg |[0 ,0 ]|,p1) \/ (LSeg p1,p2)) \/ ((((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,p2)) by XBOOLE_1:4
.= (((LSeg |[0 ,0 ]|,p1) \/ (LSeg p1,p2)) \/ (LSeg p2,|[1,0 ]|)) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) by XBOOLE_1:4
.= (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[1,0 ]|) by A3, A77, TOPREAL1:13
.= R^2-unit_square by TOPREAL1:def 4, XBOOLE_1:4 ; :: thesis: P1 /\ P2 = {p1,p2}
( p1 in LSeg p1,p2 & p1 in LSeg p1,|[0 ,0 ]| ) by RLTOPSP1:69;
then p1 in (LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) by XBOOLE_0:def 4;
then A100: {p1} c= (LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) by ZFMISC_1:37;
(LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) c= {p1}
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in (LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) or a in {p1} )
assume A101: a in (LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) ; :: thesis: a in {p1}
then reconsider p = a as Point of (TOP-REAL 2) ;
( p in LSeg p1,p2 & p in LSeg |[0 ,0 ]|,p1 & p1 `2 <= p2 `2 & p1 `1 <= p2 `1 & |[0 ,0 ]| `1 <= p1 `1 ) by A5, A6, A78, A79, A84, A101, EUCLID:56, XBOOLE_0:def 4;
then ( p1 `2 <= p `2 & p `2 <= p2 `2 & p1 `1 <= p `1 & p `1 <= p1 `1 ) by TOPREAL1:9, TOPREAL1:10;
then ( p1 `1 = p `1 & p `2 = 0 ) by A5, A6, A78, A79, XXREAL_0:1;
then p = |[(p1 `1 ),0 ]| by EUCLID:57
.= p1 by A5, A6, EUCLID:57 ;
hence a in {p1} by TARSKI:def 1; :: thesis: verum
end;
then A102: (LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|) = {p1} by A100, XBOOLE_0:def 10;
( p2 in LSeg p1,p2 & p2 in LSeg |[1,0 ]|,p2 ) by RLTOPSP1:69;
then p2 in (LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) by XBOOLE_0:def 4;
then A103: {p2} c= (LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) by ZFMISC_1:37;
(LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) c= {p2}
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in (LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) or a in {p2} )
assume A104: a in (LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) ; :: thesis: a in {p2}
then reconsider p = a as Point of (TOP-REAL 2) ;
( p in LSeg p1,p2 & p in LSeg p2,|[1,0 ]| & p1 `2 <= p2 `2 & p1 `1 <= p2 `1 & p2 `1 <= |[1,0 ]| `1 ) by A5, A6, A78, A79, A84, A104, EUCLID:56, XBOOLE_0:def 4;
then ( p1 `2 <= p `2 & p `2 <= p2 `2 & p2 `1 <= p `1 & p `1 <= p2 `1 ) by TOPREAL1:9, TOPREAL1:10;
then ( p2 `1 = p `1 & p `2 = 0 ) by A5, A6, A78, A79, XXREAL_0:1;
then p = |[(p2 `1 ),0 ]| by EUCLID:57
.= p2 by A78, A79, EUCLID:57 ;
hence a in {p2} by TARSKI:def 1; :: thesis: verum
end;
then A105: (LSeg p1,p2) /\ (LSeg |[1,0 ]|,p2) = {p2} by A103, XBOOLE_0:def 10;
( (LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A83, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A106: (LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
A107: P1 /\ P2 = ((LSeg p1,p2) /\ (LSeg p1,|[0 ,0 ]|)) \/ ((LSeg p1,p2) /\ ((((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,p2))) by XBOOLE_1:23
.= {p1} \/ (((LSeg p1,p2) /\ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}) by A102, A105, XBOOLE_1:23
.= {p1} \/ ((((LSeg p1,p2) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}) by XBOOLE_1:23
.= {p1} \/ (((((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}) by XBOOLE_1:23
.= {p1} \/ (((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})) by A106, XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|))) \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:4 ;
A108: now
per cases ( p1 = |[0 ,0 ]| or p1 <> |[0 ,0 ]| ) ;
suppose A109: p1 = |[0 ,0 ]| ; :: thesis: P1 /\ P2 = {p1} \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})
A110: (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, A77, TOPREAL1:12, XBOOLE_1:26;
p1 in LSeg p1,p2 by RLTOPSP1:69;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) <> {} by A109, Lm13, XBOOLE_0:def 4;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {p1} by A109, A110, TOPREAL1:23, ZFMISC_1:39;
hence P1 /\ P2 = {p1} \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A107; :: thesis: verum
end;
suppose A111: p1 <> |[0 ,0 ]| ; :: thesis: P1 /\ P2 = {p1} \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2})
A112: (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, A77, TOPREAL1:12, XBOOLE_1:26;
now
assume |[0 ,0 ]| in (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) ; :: thesis: contradiction
then ( |[0 ,0 ]| in LSeg p1,p2 & p1 `1 <= p2 `1 ) by A5, A78, A84, XBOOLE_0:def 4;
then p1 `1 = 0 by A5, A6, Lm4, TOPREAL1:9;
hence contradiction by A5, A6, A111, EUCLID:57; :: thesis: verum
end;
then {|[0 ,0 ]|} <> (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by ZFMISC_1:37;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {} by A112, TOPREAL1:23, ZFMISC_1:39;
hence P1 /\ P2 = {p1} \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ {p2}) by A107; :: thesis: verum
end;
end;
end;
now end;
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
suppose A117: q `1 < p `1 ; :: thesis: ex P1 being Element of K21(the carrier of (TOP-REAL 2)) ex P2 being Element of K21(the carrier of (TOP-REAL 2)) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )

take P1 = LSeg p1,p2; :: thesis: ex P2 being Element of K21(the carrier of (TOP-REAL 2)) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )

take P2 = (LSeg p1,|[1,0 ]|) \/ ((((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,0 ]|,p2)); :: thesis: ( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
thus P1 is_an_arc_of p1,p2 by A1, TOPREAL1:15; :: thesis: ( P2 is_an_arc_of p1,p2 & P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
A118: now
assume A119: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,p2) <> {} ; :: thesis: contradiction
consider a being Element of (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,p2);
reconsider p = a as Point of (TOP-REAL 2) by A119, TARSKI:def 3;
( p in LSeg p1,|[1,0 ]| & p in LSeg |[0 ,0 ]|,p2 & p1 `1 <= |[1,0 ]| `1 & |[0 ,0 ]| `1 <= p2 `1 ) by A5, A6, A78, A79, A119, EUCLID:56, XBOOLE_0:def 4;
then ( p1 `1 <= p `1 & p `1 <= p2 `1 ) by TOPREAL1:9;
hence contradiction by A5, A78, A117, XXREAL_0:2; :: thesis: verum
end;
A120: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, Lm17, TOPREAL1:12, XBOOLE_1:26;
now end;
then {|[0 ,0 ]|} <> (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by ZFMISC_1:37;
then A121: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {} by A120, TOPREAL1:23, ZFMISC_1:39;
( (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A8, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A122: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
A123: (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) c= {|[1,0 ]|} by A3, Lm17, TOPREAL1:12, TOPREAL1:22, XBOOLE_1:26;
|[1,0 ]| in LSeg p1,|[1,0 ]| by RLTOPSP1:69;
then A124: (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) <> {} by Lm18, XBOOLE_0:def 4;
A125: (LSeg p1,|[1,0 ]|) /\ ((((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,0 ]|,p2)) = ((LSeg p1,|[1,0 ]|) /\ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|))) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,p2)) by XBOOLE_1:23
.= ((LSeg p1,|[1,0 ]|) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) by A118, XBOOLE_1:23
.= ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|)) by A121, XBOOLE_1:23
.= {|[1,0 ]|} by A122, A123, A124, ZFMISC_1:39 ;
A126: (LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|) is_an_arc_of |[1,0 ]|,|[0 ,1]| by Lm4, TOPREAL1:15, TOPREAL1:16, TOPREAL1:24;
((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) by XBOOLE_1:23
.= {|[0 ,1]|} by Lm3, TOPREAL1:21 ;
then A127: ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|) is_an_arc_of |[1,0 ]|,|[0 ,0 ]| by A126, TOPREAL1:16;
A128: (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,0 ]|,p2) c= {|[0 ,0 ]|} by A77, Lm14, TOPREAL1:12, TOPREAL1:23, XBOOLE_1:26;
|[0 ,0 ]| in LSeg |[0 ,0 ]|,p2 by RLTOPSP1:69;
then (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,0 ]|,p2) <> {} by Lm13, XBOOLE_0:def 4;
then A129: (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,0 ]|,p2) = {|[0 ,0 ]|} by A128, ZFMISC_1:39;
A130: (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2) c= (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) by A77, Lm14, TOPREAL1:12, XBOOLE_1:26;
then {|[1,0 ]|} <> (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2) by ZFMISC_1:37;
then A131: (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2) = {} by A130, TOPREAL1:22, ZFMISC_1:39;
( (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2) c= (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A82, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A132: (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2) = {} by XBOOLE_1:3;
(((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) /\ (LSeg |[0 ,0 ]|,p2) = (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[0 ,0 ]|,p2)) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[0 ,0 ]|,p2)) by XBOOLE_1:23
.= (((LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,p2))) \/ {|[0 ,0 ]|} by A129, XBOOLE_1:23
.= {|[0 ,0 ]|} by A131, A132 ;
then (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,0 ]|,p2) is_an_arc_of |[1,0 ]|,p2 by A127, TOPREAL1:16;
hence P2 is_an_arc_of p1,p2 by A125, TOPREAL1:17; :: thesis: ( P1 \/ P2 = R^2-unit_square & P1 /\ P2 = {p1,p2} )
thus P1 \/ P2 = ((LSeg p2,p1) \/ (LSeg p1,|[1,0 ]|)) \/ ((((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,0 ]|,p2)) by XBOOLE_1:4
.= ((LSeg |[0 ,0 ]|,p2) \/ ((LSeg p2,p1) \/ (LSeg p1,|[1,0 ]|))) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) by XBOOLE_1:4
.= (LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) by A3, A77, TOPREAL1:13
.= (LSeg |[0 ,0 ]|,|[1,0 ]|) \/ ((LSeg |[1,0 ]|,|[1,1]|) \/ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) by XBOOLE_1:4
.= R^2-unit_square by TOPREAL1:def 4, XBOOLE_1:4 ; :: thesis: P1 /\ P2 = {p1,p2}
( p1 in LSeg p1,p2 & p1 in LSeg p1,|[1,0 ]| ) by RLTOPSP1:69;
then p1 in (LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) by XBOOLE_0:def 4;
then A133: {p1} c= (LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) by ZFMISC_1:37;
(LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) c= {p1}
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in (LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) or a in {p1} )
assume A134: a in (LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) ; :: thesis: a in {p1}
then reconsider p = a as Point of (TOP-REAL 2) ;
( p in LSeg p2,p1 & p in LSeg p1,|[1,0 ]| & p2 `2 <= p1 `2 & p2 `1 <= p1 `1 & p1 `1 <= |[1,0 ]| `1 ) by A5, A6, A78, A79, A117, A134, EUCLID:56, XBOOLE_0:def 4;
then ( p2 `2 <= p `2 & p `2 <= p1 `2 & p1 `1 <= p `1 & p `1 <= p1 `1 ) by TOPREAL1:9, TOPREAL1:10;
then ( p1 `1 = p `1 & p `2 = 0 ) by A5, A6, A78, A79, XXREAL_0:1;
then p = |[(p1 `1 ),0 ]| by EUCLID:57
.= p1 by A5, A6, EUCLID:57 ;
hence a in {p1} by TARSKI:def 1; :: thesis: verum
end;
then A135: (LSeg p1,p2) /\ (LSeg p1,|[1,0 ]|) = {p1} by A133, XBOOLE_0:def 10;
( p2 in LSeg p1,p2 & p2 in LSeg |[0 ,0 ]|,p2 ) by RLTOPSP1:69;
then p2 in (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) by XBOOLE_0:def 4;
then A136: {p2} c= (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) by ZFMISC_1:37;
(LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) c= {p2}
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) or a in {p2} )
assume A137: a in (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) ; :: thesis: a in {p2}
then reconsider p = a as Point of (TOP-REAL 2) ;
( p in LSeg p2,p1 & p in LSeg |[0 ,0 ]|,p2 & p2 `1 <= p1 `1 & p2 `2 <= p1 `2 & |[0 ,0 ]| `1 <= p2 `1 ) by A5, A6, A78, A79, A117, A137, EUCLID:56, XBOOLE_0:def 4;
then ( p2 `2 <= p `2 & p `2 <= p1 `2 & p2 `1 <= p `1 & p `1 <= p2 `1 ) by TOPREAL1:9, TOPREAL1:10;
then ( p2 `1 = p `1 & p `2 = 0 ) by A5, A6, A78, A79, XXREAL_0:1;
then p = |[(p2 `1 ),0 ]| by EUCLID:57
.= p2 by A78, A79, EUCLID:57 ;
hence a in {p2} by TARSKI:def 1; :: thesis: verum
end;
then A138: (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,p2) = {p2} by A136, XBOOLE_0:def 10;
( (LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} ) by A83, TOPREAL1:25, XBOOLE_0:def 7, XBOOLE_1:26;
then A139: (LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by XBOOLE_1:3;
A140: P1 /\ P2 = {p1} \/ ((LSeg p1,p2) /\ ((((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ (LSeg |[0 ,0 ]|,p2))) by A135, XBOOLE_1:23
.= {p1} \/ (((LSeg p1,p2) /\ (((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[0 ,1]|))) \/ {p2}) by A138, XBOOLE_1:23
.= {p1} \/ ((((LSeg p1,p2) /\ ((LSeg |[1,0 ]|,|[1,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|))) \/ {p2}) by XBOOLE_1:23
.= {p1} \/ (((((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ ((LSeg p1,p2) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|))) \/ {p2}) by XBOOLE_1:23
.= {p1} \/ (((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|)) \/ (((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ {p2})) by A139, XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ (((LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ {p2}) by XBOOLE_1:4 ;
A141: now
per cases ( p2 = |[0 ,0 ]| or p2 <> |[0 ,0 ]| ) ;
suppose A142: p2 = |[0 ,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}
A143: (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, A77, TOPREAL1:12, XBOOLE_1:26;
p2 in LSeg p1,p2 by RLTOPSP1:69;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) <> {} by A142, Lm13, XBOOLE_0:def 4;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {p2} by A142, A143, TOPREAL1:23, ZFMISC_1:39;
hence P1 /\ P2 = ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2} by A140; :: thesis: verum
end;
suppose A144: p2 <> |[0 ,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2}
A145: (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by A3, A77, TOPREAL1:12, XBOOLE_1:26;
now
assume |[0 ,0 ]| in (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) ; :: thesis: contradiction
then ( |[0 ,0 ]| in LSeg p2,p1 & p2 `1 <= p1 `1 ) by A5, A78, A117, XBOOLE_0:def 4;
then p2 `1 = 0 by A78, A79, Lm4, TOPREAL1:9;
hence contradiction by A78, A79, A144, EUCLID:57; :: thesis: verum
end;
then {|[0 ,0 ]|} <> (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by ZFMISC_1:37;
then (LSeg p1,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {} by A145, TOPREAL1:23, ZFMISC_1:39;
hence P1 /\ P2 = ({p1} \/ ((LSeg p1,p2) /\ (LSeg |[1,0 ]|,|[1,1]|))) \/ {p2} by A140; :: thesis: verum
end;
end;
end;
now end;
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
end;
end;
hence ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} ) ; :: thesis: verum
end;
suppose A150: p2 in LSeg |[1,0 ]|,|[1,1]| ; :: thesis: ex P1, P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

then A151: ex q being Point of (TOP-REAL 2) st
( q = p2 & q `1 = 1 & q `2 <= 1 & q `2 >= 0 ) by TOPREAL1:19;
A152: LSeg p2,|[1,0 ]| c= LSeg |[1,0 ]|,|[1,1]| by A150, Lm18, TOPREAL1:12;
A153: LSeg p2,|[1,1]| c= LSeg |[1,0 ]|,|[1,1]| by A150, Lm20, TOPREAL1:12;
take P1 = (LSeg p1,|[1,0 ]|) \/ (LSeg |[1,0 ]|,p2); :: thesis: ex P2 being non empty Subset of (TOP-REAL 2) st
( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )

take P2 = (LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)); :: thesis: ( P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
( |[1,0 ]| in LSeg p1,|[1,0 ]| & |[1,0 ]| in LSeg |[1,0 ]|,p2 ) by RLTOPSP1:69;
then ( (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,p2) c= (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) & (LSeg |[0 ,0 ]|,|[1,0 ]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {|[1,0 ]|} & (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,p2) <> {} ) by A8, A152, TOPREAL1:22, XBOOLE_0:def 4, XBOOLE_1:27;
then ( (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,0 ]|,p2) = {|[1,0 ]|} & ( p1 <> |[1,0 ]| or p2 <> |[1,0 ]| ) ) by A1, ZFMISC_1:39;
hence P1 is_an_arc_of p1,p2 by TOPREAL1:18; :: thesis: ( P2 is_an_arc_of p1,p2 & R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
( LSeg |[0 ,0 ]|,|[0 ,1]| is_an_arc_of |[0 ,0 ]|,|[0 ,1]| & LSeg |[0 ,1]|,|[1,1]| is_an_arc_of |[0 ,1]|,|[1,1]| ) by Lm4, TOPREAL1:15;
then A154: (LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|) is_an_arc_of |[0 ,0 ]|,|[1,1]| by TOPREAL1:5, TOPREAL1:21;
A155: (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2) = {} by A153, Lm3, XBOOLE_1:3, XBOOLE_1:26;
|[1,1]| in LSeg |[1,1]|,p2 by RLTOPSP1:69;
then A156: ( (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) c= {|[1,1]|} & (LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,1]|,p2) <> {} ) by A153, Lm19, TOPREAL1:24, XBOOLE_0:def 4, XBOOLE_1:27;
((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) /\ (LSeg |[1,1]|,p2) = ((LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,1]|,p2)) \/ ((LSeg |[0 ,1]|,|[1,1]|) /\ (LSeg |[1,1]|,p2)) by XBOOLE_1:23
.= {|[1,1]|} by A155, A156, ZFMISC_1:39 ;
then A157: ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2) is_an_arc_of |[0 ,0 ]|,p2 by A154, TOPREAL1:16;
A158: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) c= {|[1,0 ]|} by A7, A153, TOPREAL1:22, XBOOLE_1:27;
now
assume |[1,0 ]| in (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) ; :: thesis: contradiction
then ( |[1,0 ]| in LSeg |[0 ,0 ]|,p1 & |[1,0 ]| in LSeg p2,|[1,1]| & |[0 ,0 ]| `1 <= p1 `1 & p2 `2 <= |[1,1]| `2 ) by A5, A6, A151, EUCLID:56, XBOOLE_0:def 4;
then ( |[1,0 ]| `1 <= p1 `1 & p2 `2 <= |[1,0 ]| `2 ) by TOPREAL1:9, TOPREAL1:10;
then ( 0 = p1 `2 & 0 = p2 `2 & 1 = p1 `1 & 1 = p2 `1 ) by A5, A6, A151, Lm4, XXREAL_0:1;
then ( p1 = |[1,0 ]| & p2 = |[1,0 ]| ) by EUCLID:57;
hence contradiction by A1; :: thesis: verum
end;
then {|[1,0 ]|} <> (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) by ZFMISC_1:37;
then A159: (LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2) = {} by A158, ZFMISC_1:39;
(LSeg p1,|[0 ,0 ]|) /\ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)) = ((LSeg p1,|[0 ,0 ]|) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[1,1]|,p2)) by XBOOLE_1:23
.= ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[0 ,0 ]|) /\ (LSeg |[0 ,1]|,|[1,1]|)) by A159, XBOOLE_1:23
.= {|[0 ,0 ]|} by A11, A13, TOPREAL1:23, ZFMISC_1:39 ;
hence P2 is_an_arc_of p1,p2 by A157, TOPREAL1:17; :: thesis: ( R^2-unit_square = P1 \/ P2 & P1 /\ P2 = {p1,p2} )
A160: LSeg |[0 ,0 ]|,|[1,0 ]| = (LSeg p1,|[1,0 ]|) \/ (LSeg p1,|[0 ,0 ]|) by A3, TOPREAL1:11;
A161: LSeg |[1,0 ]|,|[1,1]| = (LSeg |[1,1]|,p2) \/ (LSeg |[1,0 ]|,p2) by A150, TOPREAL1:11;
thus P1 \/ P2 = (LSeg |[1,0 ]|,p2) \/ ((LSeg p1,|[1,0 ]|) \/ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by XBOOLE_1:4
.= (LSeg |[1,0 ]|,p2) \/ ((LSeg |[0 ,0 ]|,|[1,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2))) by A160, XBOOLE_1:4
.= ((((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[1,0 ]|)) \/ (LSeg |[1,1]|,p2)) \/ (LSeg |[1,0 ]|,p2) by XBOOLE_1:4
.= (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[0 ,0 ]|,|[1,0 ]|)) \/ (LSeg |[1,0 ]|,|[1,1]|) by A161, XBOOLE_1:4
.= R^2-unit_square by TOPREAL1:def 4, XBOOLE_1:4 ; :: thesis: P1 /\ P2 = {p1,p2}
A162: (LSeg p1,|[1,0 ]|) /\ (LSeg p1,|[0 ,0 ]|) = {p1} by A3, TOPREAL1:14;
A163: (LSeg |[1,0 ]|,p2) /\ (LSeg |[1,1]|,p2) = {p2} by A150, TOPREAL1:14;
( (LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) c= (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) & (LSeg |[0 ,0 ]|,|[0 ,1]|) /\ (LSeg |[1,0 ]|,|[1,1]|) = {} ) by A152, TOPREAL1:26, XBOOLE_0:def 7, XBOOLE_1:26;
then A164: (LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {} by XBOOLE_1:3;
A165: P1 /\ P2 = ((LSeg p1,|[1,0 ]|) /\ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) \/ ((LSeg |[1,0 ]|,p2) /\ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by XBOOLE_1:23
.= (((LSeg p1,|[1,0 ]|) /\ (LSeg p1,|[0 ,0 ]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) \/ ((LSeg |[1,0 ]|,p2) /\ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[1,0 ]|) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ ((LSeg |[1,0 ]|,p2) /\ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by A162, XBOOLE_1:23
.= ({p1} \/ ((((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg |[1,0 ]|,p1) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ ((LSeg |[1,0 ]|,p2) /\ ((LSeg p1,|[0 ,0 ]|) \/ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|)) \/ ((LSeg |[1,0 ]|,p2) /\ (((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|)) \/ (LSeg |[1,1]|,p2)))) by A9, XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|)) \/ (((LSeg |[1,0 ]|,p2) /\ ((LSeg |[0 ,0 ]|,|[0 ,1]|) \/ (LSeg |[0 ,1]|,|[1,1]|))) \/ {p2})) by A163, XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|)) \/ ((((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|))) \/ {p2})) by XBOOLE_1:23
.= ({p1} \/ (((LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|)) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|)) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})) by A164 ;
A166: now
per cases ( p1 = |[0 ,0 ]| or p1 = |[1,0 ]| or ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ) ;
suppose A167: p1 = |[0 ,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
then A168: (LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|) = (LSeg |[1,0 ]|,p2) /\ {|[0 ,0 ]|} by RLTOPSP1:71;
not |[0 ,0 ]| in LSeg |[1,0 ]|,p2 by A152, Lm4, TOPREAL1:9;
then (LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|) = {} by A168, Lm1;
hence P1 /\ P2 = (({p1} \/ {p1}) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by A165, A167, TOPREAL1:23, XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) ;
:: thesis: verum
end;
suppose A169: p1 = |[1,0 ]| ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
then (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {|[1,0 ]|} /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) by RLTOPSP1:71;
then A170: (LSeg p1,|[1,0 ]|) /\ (LSeg |[0 ,0 ]|,|[0 ,1]|) = {} by Lm1, Lm9;
A171: (LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|) c= (LSeg |[1,0 ]|,|[1,1]|) /\ (LSeg |[0 ,0 ]|,|[1,0 ]|) by A7, A152, XBOOLE_1:27;
( p1 in LSeg |[1,0 ]|,p2 & p1 in LSeg p1,|[0 ,0 ]| ) by A169, RLTOPSP1:69;
then {} <> (LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|) by XBOOLE_0:def 4;
then (LSeg |[1,0 ]|,p2) /\ (LSeg p1,|[0 ,0 ]|) = {p1} by A169, A171, TOPREAL1:22, ZFMISC_1:39;
hence P1 /\ P2 = ({p1} \/ ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2)))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by A165, A170, XBOOLE_1:4
.= (({p1} \/ {p1}) \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) by XBOOLE_1:4
.= ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2}) ;
:: thesis: verum
end;
suppose A172: ( p1 <> |[1,0 ]| & p1 <> |[0 ,0 ]| ) ; :: thesis: P1 /\ P2 = ({p1} \/ ((LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2))) \/ (((LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|)) \/ {p2})
end;
end;
end;
now
per cases ( p2 = |[1,0 ]| or p2 = |[1,1]| or ( p2 <> |[1,1]| & p2 <> |[1,0 ]| ) ) ;
suppose A176: p2 = |[1,0 ]| ; :: thesis: P1 /\ P2 = {p1,p2}
then A177: (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2) c= {p2} by A8, TOPREAL1:22, XBOOLE_1:27;
|[1,0 ]| in LSeg p1,|[1,0 ]| by RLTOPSP1:69;
then {} <> (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2) by A176, Lm18, XBOOLE_0:def 4;
then A178: (LSeg p1,|[1,0 ]|) /\ (LSeg |[1,1]|,p2) = {p2} by A177, ZFMISC_1:39;
(LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {|[1,0 ]|} /\ (LSeg |[0 ,1]|,|[1,1]|) by A176, RLTOPSP1:71;
then (LSeg |[1,0 ]|,p2) /\ (LSeg |[0 ,1]|,|[1,1]|) = {} by Lm1, Lm10;
hence P1 /\ P2 = {p1} \/ ({p2} \/ {p2}) by A166, A178, XBOOLE_1:4
.= {p1,p2} by ENUMSET1:41 ;
:: thesis: verum
end;
suppose A181: ( p2 <> |[1,1]| & p2 <> |[1,0 ]| ) ; :: thesis: P1 /\ P2 = {p1,p2}
end;
end;
end;
hence P1 /\ P2 = {p1,p2} ; :: thesis: verum
end;
end;