let p be Point of (Topen_unit_circle c[-10] ); :: thesis: ( p = c[10] implies Circle2IntervalL is_continuous_at p )
assume A1:
p = c[10]
; :: thesis: Circle2IntervalL is_continuous_at p
set aX1 = { q where q is Point of (TOP-REAL 2) : ( q in the carrier of (Topen_unit_circle c[-10] ) & 0 <= q `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 ) } ;
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:
{ 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] )
reconsider c1 = c[10] as Point of (TOP-REAL 2) ;
A4:
c1 `2 = 0
by EUCLID:56;
c[10] is Point of (Topen_unit_circle c[-10] )
by Lm16, Th24;
then A5:
( 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 ) } & 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;
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 A2, A3;
set X1 = (Topen_unit_circle c[-10] ) | aX1;
set X2 = (Topen_unit_circle c[-10] ) | aX2;
A6:
the carrier of ((Topen_unit_circle c[-10] ) | aX1) = aX1
by PRE_TOPC:29;
reconsider x1 = p as Point of ((Topen_unit_circle c[-10] ) | aX1) by A1, A5, PRE_TOPC:29;
A7:
the carrier of ((Topen_unit_circle c[-10] ) | aX2) = aX2
by PRE_TOPC:29;
reconsider x2 = p as Point of ((Topen_unit_circle c[-10] ) | aX2) by A1, A5, PRE_TOPC:29;
A8:
Topen_unit_circle c[-10] is SubSpace of Topen_unit_circle c[-10]
by TSEP_1:2;
the carrier of (Topen_unit_circle c[-10] ) = aX1 \/ aX2
then A10:
Topen_unit_circle c[-10] = ((Topen_unit_circle c[-10] ) | aX1) union ((Topen_unit_circle c[-10] ) | aX2)
by A6, A7, A8, TSEP_1:def 2;
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | aX1) is continuous
by Lm59;
then A11:
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | aX1) is_continuous_at x1
by TMAP_1:49;
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | aX2) is continuous
by Lm60;
then
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | aX2) is_continuous_at x2
by TMAP_1:49;
hence
Circle2IntervalL is_continuous_at p
by A10, A11, TMAP_1:125; :: thesis: verum