A equals open parentheses table row cell 1 space space space end cell 2 end table close parentheses space space space comma space space space B equals open parentheses table row 3 row 2 end table close parentheses فان A cross times B equals
open parentheses space space 7 space space close parentheses
open parentheses table row 3 row 4 end table close parentheses
open parentheses table row cell 3 space space space end cell 4 end table close parentheses
right to left empty set
