let A, A' be Cell of d,G; ( ex l, r being Element of REAL d st
( A = cell l,r & ( for i being Element of Seg d holds
( r . i < l . i & [(l . i),(r . i)] is Gap of G . i ) ) ) & ex l, r being Element of REAL d st
( A' = cell l,r & ( for i being Element of Seg d holds
( r . i < l . i & [(l . i),(r . i)] is Gap of G . i ) ) ) implies A = A' )
given l, r being Element of REAL d such that A19:
A = cell l,r
and
A20:
for i being Element of Seg d holds
( r . i < l . i & [(l . i),(r . i)] is Gap of G . i )
; ( for l, r being Element of REAL d holds
( not A' = cell l,r or ex i being Element of Seg d st
( r . i < l . i implies not [(l . i),(r . i)] is Gap of G . i ) ) or A = A' )
given l', r' being Element of REAL d such that A21:
A' = cell l',r'
and
A22:
for i being Element of Seg d holds
( r' . i < l' . i & [(l' . i),(r' . i)] is Gap of G . i )
; A = A'
reconsider l = l, r = r, l' = l', r' = r' as Function of Seg d, REAL by Def4;
then
l = l'
by FUNCT_2:113;
hence
A = A'
by A19, A21, A23, FUNCT_2:113; verum