Setoid.quotientKerEquivRange

{α : Type u_1} → {β : Type u_2} → (f : α → β) → Quotient (Setoid.ker f) ≃ ↑(Set.range f)

The first isomorphism theorem for sets: the quotient of α by the kernel of a function f bijects with f's image.

Defined in: Mathlib.Data.Setoid.Basic
Cited by: 2 results in Mathlib
Foundations: Depth 21 from the axioms · uses propext, Classical.choice, Quot.sound

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