Cardinal.add_eq_self

∀ {c : Cardinal.{u_1}}, Cardinal.aleph0 ≤ c → c + c = c

If α is an infinite type, then α ⊕ α and α have the same cardinality.

Defined in: Mathlib.SetTheory.Cardinal.Arithmetic
Cited by: 4 results in Mathlib
Foundations: Depth 101 from the axioms · uses propext, Classical.choice, Quot.sound

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