
big list - Conjectures that have been disproved with extremely large ...
Jul 23, 2010 · The first counterexample found has 96 vertices. The "least" counterexample known has 54 vertices. Heidetniemi conjecture Chromatic number of tensor product of finite undirected simple …
Prove that a counterexample exists without knowing one
Mar 13, 2014 · 0 "Prove that a counterexample exists without knowing one". The existence of continuous nowhere differentiable function can be proved without constructing one. In fact, a "typical" …
Advice on finding counterexamples - Mathematics Stack Exchange
Apr 1, 2015 · I am reaching out for specific advice on how one should go about finding counterexamples. It seems almost every time I've ever attempted a "find a counterexample" problem, I have to cheat by …
What is an example of a proof by minimal counterexample?
Nov 18, 2018 · If there aren't any counterexamples, the theorem is true, and we're done, so it's only the case where there is a counterexample that we have to deal with. This method of proof goes back (at …
logic - Using truth tables to evaluate an argument and provide ...
Dec 18, 2016 · These 3 statements aren't even related and it does not matter for a good counterexample. All that matters is that the atomic statements you choose for J, K and L are chosen …
Using proof by contradiction and a counter example.
Jul 13, 2017 · This $3$ is also a counterexample to the statement "all natural numbers are even". A proof by contradiction is a proof of a statement by assuming there is a counterexample and then …
How are proofs formatted when the answer is a counterexample?
Suppose it is asked: Prove or find a counterexample: the sum of two integers is odd The fact that 1 + 1 = 2 is a counterexample that disproves that statement. What is the proper format in which to
Proof by contradiction using counterexample - Mathematics Stack …
Apr 6, 2016 · Why can't we use one counterexample as the contradiction to the contradicting statement? Example: Let a statement be A where a-->b. We can prove A is not true by finding a counter …
discrete mathematics - How can I provide a counterexample for this ...
Mar 9, 2016 · To give a counterexample you must interpret the argument formally, forgetting about lions & animals. The logical form is: All L's are A's, and all L's are M's; therefore all A's are M's. This is …
reference request - Formal definition of “counterexample ...
Jul 17, 2016 · What is the preferred formal definition of “counterexample” as in: zero is a counterexample for "every integer is either positive or negative". Where in the literature is the notion …