- #1
Topgun_68
- 34
- 0
Homework Statement
I am trying to find a counterexample to show why the below statement is False!
ρ = PowerSet since I couldn't find the symbol.
ρ(A x B) = ρ(A) x ρ(B)
Homework Equations
N/A
The Attempt at a Solution
Aside from googling for three days. I read/reread my Discrete Mathamatics book over and over again. I've assigned simple test cases for A & B and it always comes out true whether I calculate the powersets of A & B first, then take the cartesian product or I take the cartesian product first and then calculate the powerset.
The only solution I can come up with is assigning one set to be anything non-null and the other set to be empty or Null. For instance:
A = (1,2) B = ∅
A x B = {∅}
ρ(A x B) = {0, {∅}}
---------------------------------------------
A = (1,2) B = ∅
ρ(A) = {∅, {1}, {2}, {1,2}}
ρ(B) = {0,{∅}}
ρ(A) x ρ(B) = {(∅,∅),(1,∅),(2,∅),(1,∅),(2,∅)}
-------------------------------------------------
The only time I come up with a False counterexample is anytime one of the sets contains a ∅ so I guess I a just asking if my assessment is correct or if I am way off base. Not sure if I am calculating the cardesian product correctly when it contains a set with ∅.
Any insight would be appreciated...