ProofWiki:Potw

Current Proof of The Week Intersection of Relation with Inverse is Symmetric Relation

HOW TO USE THIS PAGE

 * 1. Select the proof P you want to put up as POTW.
 * 2. Edit P to put this at the top:




 * replacing   with today's date.


 * 3. Edit the previous POTW to change:
 * to:
 * to:


 * 4. Edit this page to:
 * (a) add the old POTW to the top of the list;
 * (b) put the new POTW into the two places where the last one was.

Previous proofs of the week

 * Between Every Two Reals Exists a Rational
 * De Méré's Paradox
 * Cauchy Condensation Test
 * Congruence of Sum of Digits to Base Less 1
 * Rule of Material Implication/Formulation 1
 * Identity of Points
 * Differentiable Function is Continuous
 * Sum of Reciprocals is Divergent/Proof 1
 * Square Root of 2 is Irrational/Classic Proof
 * Difference Between Adjacent Square Roots Converges
 * Image of Intersection under One-to-Many Relation
 * Fundamental Theorem on Equivalence Relations
 * Linear Transformation as Matrix Product
 * König's Tree Lemma
 * Mean Value Theorem
 * Brahmagupta Theorem
 * Orbit-Stabilizer Theorem
 * Variance as Expectation of Square minus Square of Expectation
 * Integrating Factors for First Order Equations
 * Cassini's Identity
 * Bayes' Theorem
 * Solution to Linear First Order Ordinary Differential Equation
 * Basis Representation Theorem
 * Odd Number Theorem
 * Euler's Number is Irrational
 * Kleene's Normal Form Theorem
 * Picard's Existence Theorem
 * Fundamental Theorem of Arithmetic
 * Peak Point Lemma
 * Closed Form for Triangular Numbers
 * Existence of Euler-Mascheroni Constant
 * Cauchy Mean Value Theorem
 * Sum of Angles of Triangle Equals Two Right Angles
 * Monotone Convergence Theorem (Real Analysis)
 * Bhaskara's Lemma
 * Conjugacy Class Equation
 * Fermat's Christmas Theorem
 * L'Hôpital's Rule
 * Banach-Tarski Paradox
 * Rolle's Theorem
 * Heron's Formula
 * Area of Circle
 * Zero and One are the only Consecutive Perfect Squares/Proof 1
 * Chinese Remainder Theorem
 * Sigma Function is Multiplicative
 * Euclid's Lemma for Prime Divisors
 * Lebesgue's Number Lemma
 * Cardano's Formula
 * Area of Square
 * Westwood's Puzzle
 * Integration by Parts
 * Euclid's Lemma
 * Combination Theorem for Sequences
 * Russell's Paradox
 * Derivative of Composite Function
 * First Sylow Theorem
 * Euler Phi Function of Integer
 * Fundamental Principle of Counting
 * Partition Equation
 * Archimedean Principle
 * Pascal's Rule
 * Division Theorem
 * Lagrange's Theorem (Group Theory)
 * Solution to Quadratic Equation
 * Handshake Lemma
 * Cantor-Bernstein-Schröder Theorem
 * Euler's Formula
 * Fermat's Little Theorem
 * Cantor's Theorem
 * Euclid's Theorem
 * Binomial Theorem
 * Existence of Rational Powers of Irrational Numbers
 * Law of Cosines
 * Pythagoras's Theorem