Homework Statement
I have problem with properties of compatible observable
Homework Equations
[AB,CD]=AB CD – CD AB ………. (1)
ABCD+ACBD-ACBD-ACDB+ACDB+CADB-CADB-CDAB ………. (2)
A{C,B}D-AC{D,B}+{C,A}DB-C{D,A}B ... (3)
The Attempt at a Solution
How can the equation (1) become (2), and eq (2)...