331 lines
12 KiB
Text
331 lines
12 KiB
Text
/-
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Copyright (c) Leonardo de Moura. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Leonardo de Moura
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-/
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module
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prelude
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import Init.Core
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namespace Lean
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structure NameGenerator where
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namePrefix : Name := `_uniq
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idx : Nat := 1
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deriving Inhabited
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/-- Syntax objects for a Lean module. -/
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structure Module where
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header : Syntax
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commands : Array Syntax
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namespace Meta
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/--
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Which constants should be unfolded?
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-/
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inductive TransparencyMode where
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/-- Unfolds all constants, even those tagged as `@[irreducible]`. -/
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| all
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/-- Unfolds all constants except those tagged as `@[irreducible]`. -/
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| default
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/-- Unfolds only constants tagged with the `@[reducible]` attribute. -/
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| reducible
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/-- Unfolds reducible constants and constants tagged with the `@[instance]` attribute. -/
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| instances
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deriving Inhabited, BEq
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/-- Which structure types should eta be used with? -/
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inductive EtaStructMode where
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/-- Enable eta for structure and classes. -/
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| all
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/-- Enable eta only for structures that are not classes. -/
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| notClasses
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/-- Disable eta for structures and classes. -/
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| none
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deriving Inhabited, BEq
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namespace DSimp
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/--
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The configuration for `dsimp`.
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Passed to `dsimp` using, for example, the `dsimp (config := {zeta := false})` syntax.
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Implementation note: this structure is only used for processing the `(config := ...)` syntax, and it is not used internally.
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It is immediately converted to `Lean.Meta.Simp.Config` by `Lean.Elab.Tactic.elabSimpConfig`.
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-/
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structure Config where
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/--
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When `true` (default: `true`), performs zeta reduction of let expressions.
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That is, `let x := v; e[x]` reduces to `e[v]`.
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See also `zetaDelta`.
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-/
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zeta : Bool := true
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/--
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When `true` (default: `true`), performs beta reduction of applications of `fun` expressions.
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That is, `(fun x => e[x]) v` reduces to `e[v]`.
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-/
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beta : Bool := true
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/--
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TODO (currently unimplemented). When `true` (default: `true`), performs eta reduction for `fun` expressions.
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That is, `(fun x => f x)` reduces to `f`.
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-/
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eta : Bool := true
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/--
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Configures how to determine definitional equality between two structure instances.
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See documentation for `Lean.Meta.EtaStructMode`.
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-/
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etaStruct : EtaStructMode := .all
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/--
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When `true` (default: `true`), reduces `match` expressions applied to constructors.
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-/
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iota : Bool := true
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/--
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When `true` (default: `true`), reduces projections of structure constructors.
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-/
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proj : Bool := true
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/--
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When `true` (default: `false`), rewrites a proposition `p` to `True` or `False` by inferring
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a `Decidable p` instance and reducing it.
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-/
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decide : Bool := false
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/--
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When `true` (default: `false`), unfolds definitions.
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This can be enabled using the `simp!` syntax.
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-/
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autoUnfold : Bool := false
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/--
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If `failIfUnchanged` is `true` (default: `true`), then calls to `simp`, `dsimp`, or `simp_all`
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will fail if they do not make progress.
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-/
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failIfUnchanged : Bool := true
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/--
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If `unfoldPartialApp` is `true` (default: `false`), then calls to `simp`, `dsimp`, or `simp_all`
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will unfold even partial applications of `f` when we request `f` to be unfolded.
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-/
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unfoldPartialApp : Bool := false
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/--
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When `true` (default: `false`), local definitions are unfolded.
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That is, given a local context containing entry `x : t := e`, the free variable `x` reduces to `e`.
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-/
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zetaDelta : Bool := false
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/--
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When `index` (default : `true`) is `false`, `simp` will only use the root symbol
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to find candidate `simp` theorems. It approximates Lean 3 `simp` behavior.
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-/
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index : Bool := true
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/--
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When `true` (default : `true`), then simps will remove unused let-declarations:
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`let x := v; e` simplifies to `e` when `x` does not occur in `e`.
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-/
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zetaUnused : Bool := true
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deriving Inhabited, BEq
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end DSimp
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namespace Simp
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def defaultMaxSteps := 100000
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/--
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The configuration for `simp`.
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Passed to `simp` using, for example, the `simp (config := {contextual := true})` syntax.
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See also `Lean.Meta.Simp.neutralConfig` and `Lean.Meta.DSimp.Config`.
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-/
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structure Config where
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/--
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The maximum number of subexpressions to visit when performing simplification.
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The default is 100000.
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-/
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maxSteps : Nat := defaultMaxSteps
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/--
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When simp discharges side conditions for conditional lemmas, it can recursively apply simplification.
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The `maxDischargeDepth` (default: 2) is the maximum recursion depth when recursively applying simplification to side conditions.
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-/
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maxDischargeDepth : Nat := 2
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/--
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When `contextual` is true (default: `false`) and simplification encounters an implication `p → q`
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it includes `p` as an additional simp lemma when simplifying `q`.
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-/
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contextual : Bool := false
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/--
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When true (default: `true`) then the simplifier caches the result of simplifying each subexpression, if possible.
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-/
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memoize : Bool := true
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/--
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When `singlePass` is `true` (default: `false`), the simplifier runs through a single round of simplification,
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which consists of running pre-methods, recursing using congruence lemmas, and then running post-methods.
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Otherwise, when it is `false`, it iteratively applies this simplification procedure.
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-/
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singlePass : Bool := false
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/--
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When `true` (default: `true`), performs zeta reduction of let expressions.
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That is, `let x := v; e[x]` reduces to `e[v]`.
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See also `zetaDelta`.
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-/
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zeta : Bool := true
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/--
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When `true` (default: `true`), performs beta reduction of applications of `fun` expressions.
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That is, `(fun x => e[x]) v` reduces to `e[v]`.
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-/
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beta : Bool := true
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/--
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TODO (currently unimplemented). When `true` (default: `true`), performs eta reduction for `fun` expressions.
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That is, `(fun x => f x)` reduces to `f`.
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-/
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eta : Bool := true
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/--
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Configures how to determine definitional equality between two structure instances.
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See documentation for `Lean.Meta.EtaStructMode`.
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-/
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etaStruct : EtaStructMode := .all
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/--
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When `true` (default: `true`), reduces `match` expressions applied to constructors.
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-/
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iota : Bool := true
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/--
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When `true` (default: `true`), reduces projections of structure constructors.
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-/
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proj : Bool := true
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/--
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When `true` (default: `false`), rewrites a proposition `p` to `True` or `False` by inferring
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a `Decidable p` instance and reducing it.
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-/
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decide : Bool := false
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/-- When `true` (default: `false`), simplifies simple arithmetic expressions. -/
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arith : Bool := false
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/--
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When `true` (default: `false`), unfolds definitions.
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This can be enabled using the `simp!` syntax.
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-/
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autoUnfold : Bool := false
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/--
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When `true` (default: `true`) then switches to `dsimp` on dependent arguments
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if there is no congruence theorem that would allow `simp` to visit them.
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When `dsimp` is `false`, then the argument is not visited.
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-/
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dsimp : Bool := true
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/--
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If `failIfUnchanged` is `true` (default: `true`), then calls to `simp`, `dsimp`, or `simp_all`
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will fail if they do not make progress.
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-/
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failIfUnchanged : Bool := true
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/--
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If `ground` is `true` (default: `false`), then ground terms are reduced.
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A term is ground when it does not contain free or meta variables.
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Reduction is interrupted at a function application `f ...` if `f` is marked to not be unfolded.
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Ground term reduction applies `@[seval]` lemmas.
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-/
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ground : Bool := false
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/--
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If `unfoldPartialApp` is `true` (default: `false`), then calls to `simp`, `dsimp`, or `simp_all`
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will unfold even partial applications of `f` when we request `f` to be unfolded.
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-/
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unfoldPartialApp : Bool := false
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/--
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When `true` (default: `false`), local definitions are unfolded.
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That is, given a local context containing entry `x : t := e`, the free variable `x` reduces to `e`.
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-/
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zetaDelta : Bool := false
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/--
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When `index` (default : `true`) is `false`, `simp` will only use the root symbol
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to find candidate `simp` theorems. It approximates Lean 3 `simp` behavior.
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-/
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index : Bool := true
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/--
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If `implicitDefEqProofs := true`, `simp` does not create proof terms when the
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input and output terms are definitionally equal.
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-/
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implicitDefEqProofs : Bool := true
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/--
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When `true` (default : `true`), then simps will remove unused let-declarations:
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`let x := v; e` simplifies to `e` when `x` does not occur in `e`.
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-/
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zetaUnused : Bool := true
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deriving Inhabited, BEq
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-- Configuration object for `simp_all`
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structure ConfigCtx extends Config where
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contextual := true
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/--
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A neutral configuration for `simp`, turning off all reductions and other built-in simplifications.
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-/
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def neutralConfig : Simp.Config := {
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zeta := false
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beta := false
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eta := false
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iota := false
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proj := false
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decide := false
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arith := false
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autoUnfold := false
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ground := false
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zetaDelta := false
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zetaUnused := false
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}
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structure NormCastConfig extends Simp.Config where
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zeta := false
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beta := false
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eta := false
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proj := false
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iota := false
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end Simp
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/-- Configuration for which occurrences that match an expression should be rewritten. -/
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inductive Occurrences where
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/-- All occurrences should be rewritten. -/
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| all
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/-- A list of indices for which occurrences should be rewritten. -/
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| pos (idxs : List Nat)
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/-- A list of indices for which occurrences should not be rewritten. -/
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| neg (idxs : List Nat)
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deriving Inhabited, BEq
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instance : Coe (List Nat) Occurrences := ⟨.pos⟩
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/--
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Configuration for the `extract_lets` tactic.
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-/
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structure ExtractLetsConfig where
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/-- If true (default: false), extract lets from subterms that are proofs.
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Top-level lets are always extracted. -/
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proofs : Bool := false
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/-- If true (default: true), extract lets from subterms that are types.
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Top-level lets are always extracted. -/
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types : Bool := true
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/-- If true (default: false), extract lets from subterms that are implicit arguments. -/
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implicits : Bool := false
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/-- If false (default: true), extracts only top-level lets, otherwise allows descending into subterms.
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When false, `proofs` and `types` are ignored, and lets appearing in the types or values of the
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top-level lets are not themselves extracted. -/
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descend : Bool := true
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/-- If true (default: true), descend into forall/lambda/let bodies when extracting. Only relevant when `descend` is true. -/
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underBinder : Bool := true
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/-- If true (default: false), eliminate unused lets rather than extract them. -/
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usedOnly : Bool := false
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/-- If true (default: true), reuse local declarations that have syntactically equal values.
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Note that even when false, the caching strategy for `extract_let`s may result in fewer extracted let bindings than expected. -/
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merge : Bool := true
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/-- When merging is enabled, if true (default: true), make use of pre-existing local definitions in the local context. -/
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useContext : Bool := true
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/-- If true (default: false), then once `givenNames` is exhausted, stop extracting lets. Otherwise continue extracting lets. -/
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onlyGivenNames : Bool := false
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/-- If true (default: false), then when no name is provided for a 'let' expression, the name is used as-is without making it be inaccessible.
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The name still might be inaccessible if the binder name was. -/
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preserveBinderNames : Bool := false
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/-- If true (default: false), lift non-extractable `let`s as far out as possible. -/
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lift : Bool := false
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/--
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Configuration for the `lift_lets` tactic.
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-/
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structure LiftLetsConfig extends ExtractLetsConfig where
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lift := true
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preserveBinderNames := true
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end Lean.Meta
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