# Documentation

Lean.Meta.Tactic.Delta

def Lean.Meta.delta? (e : Lean.Expr) (p : optParam () fun x => true) :
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def Lean.Meta.deltaExpand (e : Lean.Expr) (p : ) :

Low-level delta expansion. It is used to implement equation lemmas and elimination principles for recursive definitions.

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def Lean.MVarId.deltaTarget (mvarId : Lean.MVarId) (p : ) :

Delta expand declarations that satisfy p at mvarId type.

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def Lean.MVarId.deltaLocalDecl (mvarId : Lean.MVarId) (fvarId : Lean.FVarId) (p : ) :

Delta expand declarations that satisfy p at fvarId type.

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def Lean.Meta.deltaLocalDecl (mvarId : Lean.MVarId) (fvarId : Lean.FVarId) (p : ) :
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