Proof of Duality (cont’d)

Now, do variable replacement: a = A’, b = B’, etc. Thus:
- f( a, b, c, …, 1, 0, •, + ) = g( a, b, c, …, 0, 1, +, • )
Now, do another variable replacement: A = a, B = b, etc. Thus:
- f( A, B, C, …, 1, 0, •, + ) = g( A, B, C, …, 0, 1, +, • )
By the definition of dual, this is:
- f( A, B, C, …, 0, 1, +, • )D = g( A, B, C, …, 0, 1, +, • )D
Or:
- SD = TD