Basic tactics and utilities for tactic writing

This file defines some basic utilities for tactic writing, and also

• a dummy variables macro (which warns that the Lean 4 name is variable)
• the introv tactic, which allows the user to automatically introduce the variables of a theorem and explicitly name the non-dependent hypotheses,
• an assumption macro, calling the assumption tactic on all goals
• the tactics match_target, clear_aux_decl (clearing all auxiliary declarations from the context) and clear_value (which clears the bodies of given local definitions, changing them into regular hypotheses).

def Mathlib.Tactic.variables : Lean.ParserDescr

Syntax for the variables command: this command is just a stub, and merely warns that it has been renamed to variable in Lean 4.

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def Mathlib.Tactic.elabVariables : Lean.Elab.Command.CommandElab

The variables command: this is just a stub, and merely warns that it has been renamed to variable in Lean 4.

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def Mathlib.Tactic.pushFVarAliasInfo {m : Type → Type} [Monad m] [Lean.Elab.MonadInfoTree m] (oldFVars : Array Lean.FVarId) (newFVars : Array Lean.FVarId) (newLCtx : Lean.LocalContext) : m Unit

Given two arrays of FVarIds, one from an old local context and the other from a new local context, pushes FVarAliasInfos into the info tree for corresponding pairs of FVarIds. Recall that variables linked this way should be considered to be semantically identical.

The effect of this is, for example, the unused variable linter will see that variables from the first array are used if corresponding variables in the second array are used.

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def Mathlib.Tactic.introv : Lean.ParserDescr

The tactic introv allows the user to automatically introduce the variables of a theorem and explicitly name the non-dependent hypotheses. Any dependent hypotheses are assigned their default names.

Examples:

example : ∀ a b : Nat, a = b → b = a := by
  introv h,
  exact h.symm

The state after introv h is

a b : ℕ,
h : a = b
⊢ b = a

example : ∀ a b : Nat, a = b → ∀ c, b = c → a = c := by
  introv h₁ h₂,
  exact h₁.trans h₂

The state after introv h₁ h₂ is

a b : ℕ,
h₁ : a = b,
c : ℕ,
h₂ : b = c
⊢ a = c

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def Mathlib.Tactic.evalIntrov : Lean.Elab.Tactic.Tactic

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partial def Mathlib.Tactic.evalIntrov.introsDep : Lean.Elab.Tactic.TacticM Unit

def Mathlib.Tactic.evalIntrov.intro1PStep : Lean.Elab.Tactic.TacticM Unit

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• Mathlib.Tactic.evalIntrov.intro1PStep = Lean.Elab.Tactic.liftMetaTactic fun (goal : Lean.MVarId) => do let __discr ← goal.intro1P match __discr with | (fst, goal) => pure [goal]

def Mathlib.Tactic.tacticAssumption' : Lean.ParserDescr

Try calling assumption on all goals; succeeds if it closes at least one goal.

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• Mathlib.Tactic.tacticAssumption' = Lean.ParserDescr.node `Mathlib.Tactic.tacticAssumption' 1024 (Lean.ParserDescr.nonReservedSymbol "assumption'" false)

def Mathlib.Tactic.tacticMatch_target_ : Lean.ParserDescr

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def Mathlib.Tactic.clearAuxDecl : Lean.ParserDescr

This tactic clears all auxiliary declarations from the context.

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• Mathlib.Tactic.clearAuxDecl = Lean.ParserDescr.node `Mathlib.Tactic.clearAuxDecl 1024 (Lean.ParserDescr.nonReservedSymbol "clear_aux_decl" false)

def Lean.MVarId.clearValue (mvarId : Lean.MVarId) (fvarId : Lean.FVarId) : Lean.MetaM Lean.MVarId

Clears the value of the local definition fvarId. Ensures that the resulting goal state is still type correct. Throws an error if it is a local hypothesis without a value.

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def Mathlib.Tactic.clearValue : Lean.ParserDescr

clear_value n₁ n₂ ... clears the bodies of the local definitions n₁, n₂ ..., changing them into regular hypotheses. A hypothesis n : α := t is changed to n : α.

The order of n₁ n₂ ... does not matter, and values will be cleared in reverse order of where they appear in the context.

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