Countable.lean`

Explanation legend Lean4 Domain Explanation Language (L4DEL)

L4DEL explanations are a separate layer. They do not change the Lean source. Intuition is explanatory prose; numbered items are a reading path; sources link the wording back to evidence.

L4DEL: Lean4 Domain Explanation Language

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Project sources: Pinned project documentation, Pinned FLT blueprint introduction

2 declarations, 0 contain sorry, 0 declared as axioms

Countable

Material destined for Mathlib.

Imports (3)

Imported by 5 files

lemma Countable.of_module_finite TODO upstream line 21 source
Source comment
TODO upstream

standard axioms: Classical.choice, Quot.sound, propext what this means
Statement uses: Semiring, Countable, AddCommMonoid, Module, Module.Finite
Proof uses: Nat, Exists, Fin, Eq, Submodule, Submodule.span, Set.range, Top.top, Module.Finite.exists_fin, Eq.mpr, Set.Countable, Set.univ, id, congrArg, Eq.symm, propext, Set.countable_univ_iff, Subtype, Membership.mem, inferInstance and 1 more
6 instances, coercions and auxiliary constants left out.

Tactic trace: 4 steps
Open to load the checked before-and-after goal states.
```
lemma Countable.of_module_finite (R M : Type*) [Semiring R] [Countable R]
    [AddCommMonoid M] [Module R M] [Module.Finite R M] : Countable M := by
…
```
instance (instance at line 28) line 28 source