let p be Point of (TOP-REAL 2); :: thesis: ( p `2 >= 0 implies for x, a being real number
for r being real positive number st 0 <= a & a < 1 & |.(p - |[x,(r * a)]|).| > r * a holds
(+ x,r) . p > a )
assume A1:
p `2 >= 0
; :: thesis: for x, a being real number
for r being real positive number st 0 <= a & a < 1 & |.(p - |[x,(r * a)]|).| > r * a holds
(+ x,r) . p > a
A2:
p = |[(p `1 ),(p `2 )]|
by EUCLID:57;
then reconsider z = p as Element of Niemytzki-plane by A1, Lm1, Th22;
set p1 = p `1 ;
set p2 = p `2 ;
reconsider p2 = p `2 as real non negative number by A1;
let x, a be real number ; :: thesis: for r being real positive number st 0 <= a & a < 1 & |.(p - |[x,(r * a)]|).| > r * a holds
(+ x,r) . p > a
let r be real positive number ; :: thesis: ( 0 <= a & a < 1 & |.(p - |[x,(r * a)]|).| > r * a implies (+ x,r) . p > a )
assume A3:
( 0 <= a & a < 1 )
; :: thesis: ( not |.(p - |[x,(r * a)]|).| > r * a or (+ x,r) . p > a )
then reconsider a' = a as real non negative number ;
reconsider ra = r * a as Real by XREAL_0:def 1;
assume A4:
|.(p - |[x,(r * a)]|).| > r * a
; :: thesis: (+ x,r) . p > a
A5:
(+ x,r) . z in the carrier of I[01]
by FUNCT_2:7;
|.(|[x,0 ]| - |[x,(r * a)]|).| =
|.(|[x,(r * a)]| - |[x,0 ]|).|
by TOPRNS_1:28
.=
|.|[(x - x),(ra - 0 )]|.|
by EUCLID:66
.=
abs ra
by TOPREAL6:31
.=
r * a'
by ABSVALUE:def 1
;
then A6:
( p `1 <> x or p2 <> 0 )
by A4, EUCLID:57;
per cases
( a = 0 or (+ x,r) . p = 1 or ( a > 0 & (+ x,r) . z <> 1 ) )
by A3;
suppose A8:
(
a > 0 &
(+ x,r) . z <> 1 )
;
:: thesis: (+ x,r) . p > aA9:
(
|[((p `1 ) - x),(p2 - 0 )]| `1 = (p `1 ) - x &
|[((p `1 ) - x),p2]| `2 = p2 )
by EUCLID:56;
not
p2 is
negative
;
then A10:
p in Ball |[x,r]|,
r
by A2, A6, A8, Def5;
then A11:
(+ x,r) . p =
(|.(|[x,0 ]| - p).| ^2 ) / ((2 * r) * p2)
by A2, Def5
.=
(|.(p - |[x,0 ]|).| ^2 ) / ((2 * r) * p2)
by TOPRNS_1:28
.=
(|.|[((p `1 ) - x),(p2 - 0 )]|.| ^2 ) / ((2 * r) * p2)
by A2, EUCLID:66
.=
((((p `1 ) - x) ^2 ) + (p2 ^2 )) / ((2 * r) * p2)
by A9, JGRAPH_1:46
;
r * a >= r * 0
by A3;
then
|.(p - |[x,(r * a)]|).| ^2 > (r * a) ^2
by A4, SQUARE_1:78;
then
(
|.|[((p `1 ) - x),(p2 - (r * a))]|.| ^2 > (r * a) ^2 &
|[((p `1 ) - x),(p2 - (r * a))]| `1 = (p `1 ) - x &
|[((p `1 ) - x),(p2 - (r * a))]| `2 = p2 - (r * a) )
by A2, EUCLID:56, EUCLID:66;
then
(((p `1 ) - x) ^2 ) + ((p2 - (r * a)) ^2 ) > (r * a) ^2
by JGRAPH_1:46;
then
(((((p `1 ) - x) ^2 ) + (p2 ^2 )) - ((2 * p2) * (r * a))) + ((r * a) ^2 ) > (r * a) ^2
;
then
((((p `1 ) - x) ^2 ) + (p2 ^2 )) - (((2 * p2) * r) * a) > 0
by XREAL_1:34;
then A12:
(((p `1 ) - x) ^2 ) + (p2 ^2 ) > ((2 * p2) * r) * a
by XREAL_1:49;
(
Ball |[x,r]|,
r c= y>=0-plane &
Ball |[x,r]|,
r misses y=0-line )
by Th24, Th25;
then
(
p2 >= 0 & not
p in y=0-line & (
p2 = 0 implies
p in y=0-line ) )
by A2, A10, XBOOLE_0:3;
then reconsider p2 =
p2 as
real positive number ;
(
(+ x,r) . p > (((2 * p2) * r) * a) / ((2 * r) * p2) &
a * (((2 * p2) * r) / ((2 * r) * p2)) = a * 1 )
by A11, A12, XCMPLX_1:60, XREAL_1:76;
hence
(+ x,r) . p > a
by XCMPLX_1:75;
:: thesis: verum end; end;