EDB — 23T

Exercises

1. [23T](Proposed on 2022-10-11) (Solved on 2022-10-25) Prove that the definition [1W1]↺↻ of intersection is well posed, using the Z-F axioms. Eventually prove also that

   \begin{equation} ∀ x, x∈ ⋂_{i∈ I}C_ i \iff \left(I≠∅ ∧ ∀ i∈ I, x∈ C_ i\right)\quad . \label{eq:inters_ in_ logica} \end{equation}

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   Solution 1

   [23V]↺↻