Friday, February 8, 2008

Left-Shifting

Could use a quick reality check on the definition of left-shift (q6b); there seems to be more than one consistent interpretation.

What would the following set become with i=1, j=3?
{ 011, 101, 111, 001 }

Thanks. :-)

4 comments:

Anonymous said...

According to what I understood, it should become

{ 110, 101, 111, 100 }

Aaron said...

So is the "shift" just a swap? I would have interpreted shift to mean

011 -> 101

Ryan O'Donnell said...

Anon. is correct:
011 -> 110
101 -> doesn't change
111 -> doesn't change
001 -> 100

In set language, each A is replaced by A \setminus {j} \cup {i} (as long as that's not already in the family).

Dafna said...

Thanks, now it's clear.