`reduce` does not recurse into binder types

[JLimperg]

Prerequisites

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• Check that your issue is not already filed:
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• Reduce the issue to a minimal, self-contained, reproducible test case.
  Avoid dependencies to Mathlib or Batteries.
• Test your test case against the latest nightly release, for example on
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Description

reduce does not recurse into binder types, even with skipTypes := false. As a result, the expression computed by reduce is not the input expression's normal form (at the given transparency).

MWE:

import Lean

open Lean Lean.Meta

def Foo := True

def Bar := Foo → Foo

run_meta do
  logInfo $ ← reduceAll (.const ``Bar [])
  -- Foo → True

Versions

"4.15.0-nightly-2024-11-14"

Impact

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