Set Theory: Proving A-(BUC)=(A\cup B)-C

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SUMMARY

The discussion centers on proving the set theory equation A - (B ∪ C) = (A ∪ B) - C using algebraic manipulation. Participants emphasize the importance of rewriting set differences explicitly, such as A - B = A - (A ∩ B), to facilitate simplification. They suggest applying distributive and associative properties rather than De Morgan's laws for this proof. The use of Venn diagrams is also recommended for visual verification of the equality.

PREREQUISITES
  • Understanding of set theory concepts, including unions and intersections.
  • Familiarity with algebraic manipulation of sets.
  • Knowledge of De Morgan's laws and their applications.
  • Ability to interpret Venn diagrams for set relationships.
NEXT STEPS
  • Study the distributive and associative properties of set operations.
  • Explore detailed examples of set algebra proofs.
  • Research De Morgan's laws and their implications in set theory.
  • Practice using Venn diagrams to visualize complex set operations.
USEFUL FOR

Students studying set theory, educators teaching algebra of sets, and anyone interested in mathematical proofs involving set operations.

Carmen12
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Homework Statement





[A-(BUC)]U[(A\cup B)-C]U[(A\cap C)-B]U[A\capB\capC];

The Attempt at a Solution



Sorry about the crappy formatting (btw).
Anyway, I'm trying to "prove" that this is is equal to A. So basically cancelling out the Bs and Cs? I'm not sure how to go about this. de morgan's laws? *sigh* I tested it with Venn Diagrams and it is equal to A.
 
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I would start be re-writing the subtractions a little more explicitly, as an example
A - B = A - A \cap B

this should lead to a few siplifications, and you should be able to apply de morgan's law more easily
 
Thank you so much! Some research on de morgan is in need!

I wish there was a calculator for this stuff. *sigh*

For the proof will just showing the calculations work? Or is there a particular way of writing it out I need?
 
just try and simplify the RHS as much as you can

and its not De Morgan's law you need, which deals with complements, its just distrbutivity & associtivity see the following

http://en.wikipedia.org/wiki/Algebra_of_sets
 

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