let T be non empty normal TopSpace; :: thesis: for A, B being closed Subset of T st A <> {} & A misses B holds
for G being Rain of A,B
for r1, r2 being Real st r1 in DOM & r2 in DOM & r1 < r2 holds
for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2
let A, B be closed Subset of T; :: thesis: ( A <> {} & A misses B implies for G being Rain of A,B
for r1, r2 being Real st r1 in DOM & r2 in DOM & r1 < r2 holds
for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2 )
assume A1:
( A <> {} & A misses B )
; :: thesis: for G being Rain of A,B
for r1, r2 being Real st r1 in DOM & r2 in DOM & r1 < r2 holds
for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2
let G be Rain of A,B; :: thesis: for r1, r2 being Real st r1 in DOM & r2 in DOM & r1 < r2 holds
for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2
let r1, r2 be Real; :: thesis: ( r1 in DOM & r2 in DOM & r1 < r2 implies for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2 )
assume A2:
( r1 in DOM & r2 in DOM & r1 < r2 )
; :: thesis: for C being Subset of T st C = (Tempest G) . r1 holds
Cl C c= (Tempest G) . r2
then A3:
( ( r1 in (halfline 0 ) \/ DYADIC or r1 in right_open_halfline 1 ) & ( r2 in (halfline 0 ) \/ DYADIC or r2 in right_open_halfline 1 ) )
by URYSOHN1:def 5, XBOOLE_0:def 3;
let C be Subset of T; :: thesis: ( C = (Tempest G) . r1 implies Cl C c= (Tempest G) . r2 )
assume A4:
C = (Tempest G) . r1
; :: thesis: Cl C c= (Tempest G) . r2
per cases
( ( r1 in halfline 0 & r2 in halfline 0 ) or ( r1 in DYADIC & r2 in halfline 0 ) or ( r1 in right_open_halfline 1 & r2 in halfline 0 ) or ( r1 in halfline 0 & r2 in DYADIC ) or ( r1 in DYADIC & r2 in DYADIC ) or ( r1 in right_open_halfline 1 & r2 in DYADIC ) or ( r1 in halfline 0 & r2 in right_open_halfline 1 ) or ( r1 in DYADIC & r2 in right_open_halfline 1 ) or ( r1 in right_open_halfline 1 & r2 in right_open_halfline 1 ) )
by A3, XBOOLE_0:def 3;
suppose A11:
(
r1 in DYADIC &
r2 in DYADIC )
;
:: thesis: Cl C c= (Tempest G) . r2then consider n1 being
Element of
NAT such that A12:
r1 in dyadic n1
by URYSOHN1:def 4;
consider n2 being
Element of
NAT such that A13:
r2 in dyadic n2
by A11, URYSOHN1:def 4;
set n =
n1 + n2;
A14:
(
dyadic n1 c= dyadic (n1 + n2) &
dyadic n2 c= dyadic (n1 + n2) )
by NAT_1:11, URYSOHN2:33;
then A15:
(Tempest G) . r1 = (G . (n1 + n2)) . r1
by A1, A2, A11, A12, Def4;
reconsider D =
G . (n1 + n2) as
Drizzle of
A,
B,
n1 + n2 by A1, Def2;
reconsider r1 =
r1,
r2 =
r2 as
Element of
dyadic (n1 + n2) by A12, A13, A14;
Cl (D . r1) c= D . r2
by A1, A2, Def1;
hence
Cl C c= (Tempest G) . r2
by A1, A2, A4, A11, A15, Def4;
:: thesis: verum end; end;