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Léreau

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  • Member since July 04 2016
  • 526 profile views
  • Last seen Apr 04 '24 at 09:08

Linear Algebra

  • Fast and intuitive way to calculate matrix multiplication
  • The idea behind (in)dependent vectors
  • Rotational invariance of the cross product
  • Levi Cevita and Kronecker Delta identity
  • Epsilon-Tensor

Logic

  • Does intuitionist logic prove the negations of some classical theorems?
  • If ∩ ≡ ∧ and ∪ ≡ ∨, then power set ≡ ???
  • Reverse Proofs
  • Are proofs necessarily based on truth?
  • How do implications distribute?
  • Intricacies when proving ∀-statements
  • Validity of the law of excluded middle
  • Is the 17-gon constructable?
  • Short proof of ∃x∀y(D(x)→D(y))

Constructive Logic

  • Constructive proof of x = y ∨ x ≠ y for natural numbers
  • What is implcation?
  • Excluded middle, double negation, contraposition and Peirce's law in minimal logic
  • Deduction of ⊢ (p → q) ∨ (q → r)
  • Deduction of PA ⊢ (irreducible → prime)