Loogle!

Result

Found 10848 declarations mentioning Option. Of these, 24 match your pattern(s).

• List.findSome? 📋 Init.Data.List.Basic
  {α : Type u} {β : Type v} (f : α → Option β) : List α → Option β
• List.findSomeRev? 📋 Init.Data.List.Basic
  {α : Type u} {β : Type v} (f : α → Option β) : List α → Option β
• Option.orElse 📋 Init.Data.Option.Basic
  {α : Type u_1} : Option α → (Unit → Option α) → Option α
• Option.tryCatch 📋 Init.Data.Option.Basic
  {α : Type u_1} (x : Option α) (handle : Unit → Option α) : Option α
• Option.bind 📋 Init.Data.Option.Basic
  {α : Type u_1} {β : Type u_2} : Option α → (α → Option β) → Option β
• Array.findSome? 📋 Init.Data.Array.Basic
  {α : Type u} {β : Type v} (f : α → Option β) (as : Array α) : Option β
• Array.findSomeRev? 📋 Init.Data.Array.Basic
  {α : Type u} {β : Type v} (f : α → Option β) (as : Array α) : Option β
• Option.bind_eq_bind 📋 Init.Data.Option.Lemmas
  {α β : Type u_1} : bind = Option.bind
• Option.orElse_eq_orElse 📋 Init.Data.Option.Lemmas
  {α : Type u_1} : HOrElse.hOrElse = Option.orElse
• List.findSomeRev?TR 📋 Init.Data.List.Impl
  {α : Type u_1} {β : Type u_2} (f : α → Option β) (l : List α) : Option β
• List.findSomeRev?_eq_findSomeRev?TR 📋 Init.Data.List.Impl
  : @List.findSomeRev? = @List.findSomeRev?TR
• Vector.findSome? 📋 Init.Data.Vector.Basic
  {α : Type u_1} {β : Type u_2} {n : ℕ} (f : α → Option β) (as : Vector α n) : Option β
• Vector.findSomeRev? 📋 Init.Data.Vector.Basic
  {α : Type u_1} {β : Type u_2} {n : ℕ} (f : α → Option β) (as : Vector α n) : Option β
• Lean.Order.Example.findF 📋 Init.Internal.Order.Basic
  (P : ℕ → Bool) (rec : ℕ → Option ℕ) (x : ℕ) : Option ℕ
• Lean.PersistentArray.findSome? 📋 Lean.Data.PersistentArray
  {α : Type u} {β : Type u_1} (t : Lean.PersistentArray α) (f : α → Option β) : Option β
• Lean.PersistentArray.findSomeRev? 📋 Lean.Data.PersistentArray
  {α : Type u} {β : Type u_1} (t : Lean.PersistentArray α) (f : α → Option β) : Option β
• Lean.LocalContext.findDecl? 📋 Lean.LocalContext
  {β : Type u_1} (lctx : Lean.LocalContext) (f : Lean.LocalDecl → Option β) : Option β
• Lean.LocalContext.findDeclRev? 📋 Lean.LocalContext
  {β : Type u_1} (lctx : Lean.LocalContext) (f : Lean.LocalDecl → Option β) : Option β
• Lean.Expr.instantiateLevelParamsCore.replaceFn 📋 Lean.Util.InstantiateLevelParams
  (s : Lean.Name → Option Lean.Level) (e : Lean.Expr) : Option Lean.Expr
• Fin.findSome? 📋 Batteries.Data.Fin.Basic
  {n : ℕ} {α : Type u_1} (f : Fin n → Option α) : Option α
• Batteries.RBMap.alter.adapt 📋 Batteries.Data.RBMap.Alter
  {α : Type u_1} {β : Type u_2} (k : α) (f : Option β → Option β) : Option (α × β) → Option (α × β)
• Lean.Name.findPrefix 📋 Mathlib.Tactic.Linter.DirectoryDependency
  {α : Type u_1} (f : Lean.Name → Option α) (n : Lean.Name) : Option α
• Aesop.Script.findFirstStep? 📋 Aesop.Script.Util
  {α β : Type} (goals : Array α) (step? : α → Option β) (stepOrder : β → ℕ) : Option (ℕ × α × β)
• Set.enumerate 📋 Mathlib.Data.Set.Enumerate
  {α : Type u_1} (sel : Set α → Option α) : Set α → ℕ → Option α

About

Loogle searches Lean and Mathlib definitions and theorems.

You can use Loogle from within the Lean4 VSCode language extension using (by default) Ctrl-K Ctrl-S. You can also try the #loogle command from LeanSearchClient, the CLI version, the Loogle VS Code extension, the lean.nvim integration or the Zulip bot.

Usage

Loogle finds definitions and lemmas in various ways:

1. By constant:
   🔍 Real.sin
   finds all lemmas whose statement somehow mentions the sine function.

2. By lemma name substring:
   🔍 "differ"
   finds all lemmas that have "differ" somewhere in their lemma name.

3. By subexpression:
   🔍 _ * (_ ^ _)
   finds all lemmas whose statements somewhere include a product where the second argument is raised to some power.

   The pattern can also be non-linear, as in
   🔍 Real.sqrt ?a * Real.sqrt ?a

   If the pattern has parameters, they are matched in any order. Both of these will find List.map:
   🔍 (?a -> ?b) -> List ?a -> List ?b
   🔍 List ?a -> (?a -> ?b) -> List ?b

4. By main conclusion:
   🔍 |- tsum _ = _ * tsum _
   finds all lemmas where the conclusion (the subexpression to the right of all → and ∀) has the given shape.

   As before, if the pattern has parameters, they are matched against the hypotheses of the lemma in any order; for example,
   🔍 |- _ < _ → tsum _ < tsum _
   will find tsum_lt_tsum even though the hypothesis f i < g i is not the last.

If you pass more than one such search filter, separated by commas Loogle will return lemmas which match all of them. The search
🔍 Real.sin, "two", tsum, _ * _, _ ^ _, |- _ < _ → _
would find all lemmas which mention the constants Real.sin and tsum, have "two" as a substring of the lemma name, include a product and a power somewhere in the type, and have a hypothesis of the form _ < _ (if there were any such lemmas). Metavariables (?a) are assigned independently in each filter.

The #lucky button will directly send you to the documentation of the first hit.

Source code

You can find the source code for this service at https://github.com/nomeata/loogle. The https://loogle.lean-lang.org/ service is provided by the Lean FRO.

This is Loogle revision 19971e9 serving mathlib revision e0654b0