#3 products in store
# Y\X  0   1      2
# 0   P0  P1    cashier
# 1   P2  exit
#
eventId,productId,location
# products are on shelf
0,P0,X0_Y0
1,P1,X1_Y0
2,P2,X0_Y1
# P1's rfid is destroyed
3,P0,X0_Y0
4,P2,X0_Y1
# Someone put P0 in his pocket and walk to exit
5,P0,X1_Y0
6,P2,X0_Y1
7,P0,exit
8,P2,X0_Y1
# customer C put P2 in his shopping cart
9,P0,X0_Y0
10,P2,X0_Y0
# C walks to cashier
11,P0,X0_Y0
12,P2,X1_Y0
# C pays for P2
13,P0,X0_Y0
14,P2,X2_Y0
# C walks to exit
15,P0,X0_Y0
16,P2,X2_Y1
# C exits store
17,P0,X0_Y0
18,P2,exit
# Only P0 stays
19,P0,X0_Y0
20,P0,X0_Y0