اذا كانت A equals open parentheses table row 1 row 2 end table close parentheses space space space space space space space space comma space space space space space space space space space B equals open parentheses table row cell 3 space space space space space end cell 1 end table close parentheses فان A plus B equals
open parentheses table row cell 4 space space space space space end cell 3 end table close parentheses
open parentheses table row 4 row 3 end table close parentheses
right to left ϕ
open parentheses space space space space 2 space space space space close parentheses