reconsider c1 = c[10] as Point of (TOP-REAL 2) ;
set aX2 = { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 >= q `2 ) } ;
set aX1 = { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 <= q `2 ) } ;
A1:
{ q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 <= q `2 ) } c= the carrier of (Topen_unit_circle c[-10])
A2:
{ q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 >= q `2 ) } c= the carrier of (Topen_unit_circle c[-10])
A3:
Topen_unit_circle c[-10] is SubSpace of Topen_unit_circle c[-10]
by TSEP_1:2;
A4:
c1 `2 = 0
by EUCLID:52;
A5:
c[10] is Point of (Topen_unit_circle c[-10])
by Lm15, Th23;
then A6:
c[10] in { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 <= q `2 ) }
by A4;
A7:
c[10] in { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 >= q `2 ) }
by A4, A5;
then reconsider aX1 = { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 <= q `2 ) } , aX2 = { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10]) & 0 >= q `2 ) } as non empty Subset of (Topen_unit_circle c[-10]) by A1, A2, A6;
set X1 = (Topen_unit_circle c[-10]) | aX1;
let p be Point of (Topen_unit_circle c[-10]); ( p = c[10] implies Circle2IntervalL is_continuous_at p )
assume A8:
p = c[10]
; Circle2IntervalL is_continuous_at p
reconsider x1 = p as Point of ((Topen_unit_circle c[-10]) | aX1) by A8, A6, PRE_TOPC:8;
set X2 = (Topen_unit_circle c[-10]) | aX2;
reconsider x2 = p as Point of ((Topen_unit_circle c[-10]) | aX2) by A8, A7, PRE_TOPC:8;
A9:
the carrier of ((Topen_unit_circle c[-10]) | aX2) = aX2
by PRE_TOPC:8;
the carrier of (Topen_unit_circle c[-10]) c= aX1 \/ aX2
then A11:
the carrier of (Topen_unit_circle c[-10]) = aX1 \/ aX2
;
Circle2IntervalL | ((Topen_unit_circle c[-10]) | aX2) is continuous
by Lm60;
then A12:
Circle2IntervalL | ((Topen_unit_circle c[-10]) | aX2) is_continuous_at x2
;
Circle2IntervalL | ((Topen_unit_circle c[-10]) | aX1) is continuous
by Lm59;
then A13:
Circle2IntervalL | ((Topen_unit_circle c[-10]) | aX1) is_continuous_at x1
;
the carrier of ((Topen_unit_circle c[-10]) | aX1) = aX1
by PRE_TOPC:8;
then
Topen_unit_circle c[-10] = ((Topen_unit_circle c[-10]) | aX1) union ((Topen_unit_circle c[-10]) | aX2)
by A9, A3, A11, TSEP_1:def 2;
hence
Circle2IntervalL is_continuous_at p
by A13, A12, TMAP_1:113; verum