from Introduction to Linear Algebra at the University of Tokyo ∀ and ∃ For every : “For all real numbers x,” “For any real number x chosen, always”

  • I thought it was easier to understand when thinking of it as “choose” in the Epsilon-Delta Method of Math Girl (blu3mo)
  • Flip the A in All and get
    • I see (or do I?) (blu3mo)

: “There exists a real number y that satisfies the condition P.”

  • Flip the E in exists and get
    • Definitely Yo (blu3mo) (takker)
  • It can also be written as
    • such that