398.lean`

Explanation legend Lean4 Domain Explanation Language (L4DEL)

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L4DEL: Lean4 Domain Explanation Language

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Project sources: Pinned project documentation, Formal Conjectures paper, arXiv v1

1 declarations, 1 contain sorry, 0 declared as axioms

Erdős Problem 398

References:

Imports (1)

FormalConjecturesUtil

Imported by 2 files

theorem Erdos398.erdos_398 Brocard's Problem Does $n! + 1 = m^2$ have integer solutions other than $n = 4, 5, 7$? sorry line 39 source
Source documentation
Brocard's Problem Does $n! + 1 = m^2$ have integer solutions other than $n = 4, 5, 7$?

depends on sorry what this means
Statement uses: Iff, True, Eq, Set, Nat, Set.ofPred, Exists, HAdd.hAdd, Nat.factorial, OfNat.ofNat, HPow.hPow, Insert.insert, Singleton.singleton
Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous
18 instances, coercions and auxiliary constants left out.

Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
```
theorem erdos_398 : answer(sorry) ↔ {n | ∃ m, n ! + 1 = m ^ 2} = {4, 5, 7} := by
…
```