Theorems · Definition · number theory
Nat.ppred
ℕ → Option ℕ
Partial predecessor operation. Returns ppred n = some m
if n = m + 1, otherwise none.
- Defined in
- Mathlib.Data.Nat.PSub
- Cited by
- 15 results in Mathlib
- Foundations
- Depth 5 from the axioms · uses no axioms
Around this declaration
Dashed lines are statement dependencies; solid lines are citations in proofs.
Cites0
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
Nothing in Mathlib beyond the foundations.
Cited by15
Results whose statement or proof uses this declaration.
- Primrec.to_compproof · cited by 40
- Computable.ofOptionproof · cited by 7
- Nat.Partrec.ppredstatement · cited by 4
- Nat.ppred_eq_somestatement and proof · cited by 2
- Partrec.option_some_iffproof · cited by 2
- Computable.bind_decode_iffproof · cited by 1
- Nat.ppred_eq_nonestatement and proof · cited by 0
- Nat.ppred_eq_predstatement · cited by 0
- Nat.ppred_succstatement · cited by 0
- Nat.ppred_zerostatement · cited by 0
- Nat.pred_eq_ppredstatement · cited by 0
- Nat.psub_addproof · cited by 0