let I be non empty set ; for J being non-Empty TopSpace-yielding ManySortedSet of I
for i being Element of I
for xi being Element of (J . i)
for Ai being Subset of (J . i) st (proj J,i) " {xi} meets (proj J,i) " Ai holds
xi in Ai
let J be non-Empty TopSpace-yielding ManySortedSet of I; for i being Element of I
for xi being Element of (J . i)
for Ai being Subset of (J . i) st (proj J,i) " {xi} meets (proj J,i) " Ai holds
xi in Ai
let i be Element of I; for xi being Element of (J . i)
for Ai being Subset of (J . i) st (proj J,i) " {xi} meets (proj J,i) " Ai holds
xi in Ai
let xi be Element of (J . i); for Ai being Subset of (J . i) st (proj J,i) " {xi} meets (proj J,i) " Ai holds
xi in Ai
let Ai be Subset of (J . i); ( (proj J,i) " {xi} meets (proj J,i) " Ai implies xi in Ai )
assume
((proj J,i) " {xi}) /\ ((proj J,i) " Ai) <> {}
; XBOOLE_0:def 7 xi in Ai
then
((proj (Carrier J),i) " {xi}) /\ ((proj J,i) " Ai) <> {}
by WAYBEL18:def 4;
then
((proj (Carrier J),i) " {xi}) /\ ((proj (Carrier J),i) " Ai) <> {}
by WAYBEL18:def 4;
then A1:
(proj (Carrier J),i) " {xi} meets (proj (Carrier J),i) " Ai
by XBOOLE_0:def 7;
Ai c= the carrier of (J . i)
;
then
Ai c= (Carrier J) . i
by YELLOW_6:9;
hence
xi in Ai
by A1, Th1; verum