let E be compact non horizontal non vertical Subset of (TOP-REAL 2); not cell ((Gauge (E,0)),2,2) c= BDD E
assume A1:
cell ((Gauge (E,0)),2,2) c= BDD E
; contradiction
E c= cell ((Gauge (E,0)),2,2)
by Th17;
then A2:
E c= BDD E
by A1;
set e = the Element of E;
A3:
BDD E misses E
by JORDAN1A:7;
the Element of E in E
;
hence
contradiction
by A2, A3, XBOOLE_0:3; verum