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The infoview always displays "No Info found", All messages is always (0).
Also after a Lean4: Project Build Project
The infoview always displays "Error updating: Error fetching goals: Client is …
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This works in Lean3:
```lean
theorem foo : ∀ {x : Type}, Type := λ (x : Type), x
```
But this fails in Lean4:
```lean
theorem foo : ∀ {x : Type}, Type := λ (x : Type) => x
/-
error: type misma…
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### Prerequisites
Please put an X between the brackets as you perform the following steps:
* [x] Check that your issue is not already filed:
https://github.com/leanprover/lean4/issues
* …
TwoFX updated
3 months ago
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Many of the theorem statements does not have formal proofs(they have the sorry tags). If I have a generated proof for a theorem how should I evaluate it, even if we have a predicted proof and ground t…
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Compare:
* Lean 4: [`exists_eq`](https://leanprover-community.github.io/mathlib4_docs/Std/Logic.html#exists_eq)
* Lean 3: [`exists_eq`](https://leanprover-community.github.io/mathlib_docs/find/exist…
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https://leanprover-community.github.io/mathlib_docs/tactic/delta_instance.html#tactic.delta_instance_handler
In lean3 there was a default derive handler which would run `delta` on the goal. That is, …
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Lean4's `≤` does not match lean3's `≤` on nats. In lean3, nat.le are inductive whereas in lean4, Nat.le is defined as the boolean version returning true. I think this instance clash will cause big pro…
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Some links of Lean recipes in README are broken due to inconsistent naming:
> See ``__, ``__, ``__ and ``__ for examples.
Only the first link works, the rest are broken because the actual file …
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It seems at least `leanpkg test` doesn't exist on lean4 (yet?), so running this on a lean4 repository just fails immediately.
I had no expectations it'd work, but perhaps a first way to fix things …
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```lean
import Std.Tactic.RCases
theorem aux (h : 0 < 2) : ∃ n : Nat, n = 2 := ⟨2, rfl⟩
example : True := by
rcases aux ?_ with ⟨x, h⟩
trivial
```
I would expect a side goal to be cre…