659db85510
This PR amends #13317 to suggest `:= (rfl)` as the recommended way to avoid a theorem to be automatically marked `[defeq]`, for consistency with existing documentation. Rationale: the special treatment of `:= rfl` is based on syntax, not the proof term, so it’s appropriate to use different syntax. And also I like the way it reads like a “muted whisper of `rfl`”.
47 lines
1.3 KiB
Text
47 lines
1.3 KiB
Text
set_option simp.rfl.checkTransparency true
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-- `myId` is at default transparency, not reducible
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def myId (n : Nat) : Nat := n
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-- LHS `myId n` and RHS `n` are only defeq if `myId` is unfolded (requires default transparency)
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/--
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warning: `myId_eq` is a `[defeq]` simp theorem, but its left-hand side
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myId n
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is not definitionally equal to the right-hand side
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n
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at `.instances` transparency. Possible solutions:
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1- use `(rfl)` as the proof
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2- mark constants occurring in the lhs and rhs as `[implicit_reducible]`
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-/
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#guard_msgs in
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@[simp] theorem myId_eq (n : Nat) : myId n = n := rfl
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#guard_msgs in
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@[simp] theorem myId_eq' (n : Nat) : myId n = n := (rfl)
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attribute [implicit_reducible] myId
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#guard_msgs in
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@[simp] theorem myId_eq'' (n : Nat) : myId n = n := rfl
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-- `implicit_reducible` version should be fine
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@[implicit_reducible] def myId2 (n : Nat) : Nat := n
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#guard_msgs in
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@[simp] theorem myId2_eq (n : Nat) : myId2 n = n := rfl
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/--
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warning: `add_zero` is a `[defeq]` simp theorem, but its left-hand side
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n + 0
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is not definitionally equal to the right-hand side
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n
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at `.instances` transparency. Possible solutions:
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1- use `(rfl)` as the proof
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2- mark constants occurring in the lhs and rhs as `[implicit_reducible]`
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-/
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#guard_msgs in
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@[simp] theorem add_zero (n : Nat) : n + 0 = n := rfl
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#guard_msgs in
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@[simp] theorem add_zero' (n : Nat) : n + 0 = n := (rfl)
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