Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question on testing logical truths for set operations

  1. Oct 31, 2014 #1
    My question is on how to answer if two statements are equal in set theory. Like De'Morgans laws for example. I'm currently reading James Munkres' book "Topology" and am working through the set theory chapters now, and this isn't the first time I've seen the material, but every time I see this type of work they always use vein-diagrams to "prove" if two statements are the same. I personally don't like vein-diagrams, they don't feel rigourus enough I suppose, so my question is there another way to work on these problems? Like a more algebraic way I suppose, not drawing circles and checking overlapping sections, just isn't the type of math I enjoy.
  2. jcsd
  3. Oct 31, 2014 #2

    Stephen Tashi

    User Avatar
    Science Advisor

    Two "expressions" might be "equal" or "not equal" but , technically, "statements" are "equivalent" or "not equivalent".

    If you want to prove that two expressions P and Q describe the same set, prove that the statement "x is a member of P " is equivalent to "x is a member of Q". For example, proving DeMorgans laws for sets can be done by using DeMorgans laws for propositions. ( such as "not (x is an elment of A or x is an element of B)" is equivalent to "x is not an element of A and x is not an element of B".
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Question testing logical Date
Chi Squared Test question Jul 23, 2015
Question on G-Test Apr 15, 2014
Question on Pearson's Chi-squared test Feb 3, 2014
Some questions about hypothesis testing Dec 1, 2012
Basic Statistics question: which test to run? Jan 24, 2012