let i, n be Element of NAT ; for E, C being compact non horizontal non vertical Subset of (TOP-REAL 2) st i <= len (Gauge (E,n)) holds
cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= UBD E
let E, C be compact non horizontal non vertical Subset of (TOP-REAL 2); ( i <= len (Gauge (E,n)) implies cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= UBD E )
assume A1:
i <= len (Gauge (E,n))
; cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= UBD E
width (Gauge (E,n)) = len (Gauge (E,n))
by JORDAN8:def 1;
then
cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) misses E
by A1, JORDAN8:15;
then A2:
cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= E `
by SUBSET_1:23;
A3:
not E ` is empty
by JORDAN2C:66;
( cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) is connected & not cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) is empty )
by A1, Th45, Th46;
then consider W being Subset of (TOP-REAL 2) such that
A4:
W is_a_component_of E `
and
A5:
cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= W
by A2, A3, GOBOARD9:3;
not W is Bounded
by A1, A5, Th48, JORDAN2C:12;
then
W is_outside_component_of E
by A4, JORDAN2C:def 3;
then
W c= UBD E
by JORDAN2C:23;
hence
cell ((Gauge (E,n)),i,(width (Gauge (E,n)))) c= UBD E
by A5, XBOOLE_1:1; verum