lean4-htt/tests/lean/run/3922.lean
Marc Huisinga 9d427fdfcf
feat: "try this" messages with support for interactivity (#10524)
This PR adds support for interactivity to the combined "try this"
messages that were introduced in #9966. In doing so, it moves the link
to apply a suggestion to a separate `[apply]` button in front of the
suggestion. Hints with diffs remain unchanged, as they did not
previously support interacting with terms in the diff, either.

<img width="379" height="256" alt="Suggestion with interactive message"
src="https://github.com/user-attachments/assets/7838ebf6-0613-46e7-bc88-468a05acbf51"
/>
2025-10-13 13:39:03 +00:00

46 lines
1.2 KiB
Text

/-!
# Issue 3922
The `apply?` tactic would apply `symm` to every hypothesis in the local context,
leading to these new hypotheses being included in the term even if they weren't used.
They also created unelaboratable terms such as `?_ (id (r.symm h₂))`.
-/
set_option linter.unusedVariables false
-- set up a binary relation
axiom r : Nat → Nat → Prop
-- that is symmetric
axiom r.symm {a b : Nat} : r a b → r b a
-- and has some other property
axiom r.trans {a b c : Nat} : r a b → r b c → r a c
/--
info: Try this:
[apply] refine r.symm ?_
-- Remaining subgoals:
-- ⊢ r a c
---
info: found a partial proof, but the corresponding tactic failed:
(expose_names; refine r.trans ?_ ?_)
It may be possible to correct this proof by adding type annotations, explicitly specifying implicit arguments, or eliminating unnecessary function abstractions.
---
warning: declaration uses 'sorry'
-/
#guard_msgs (ordering := sorted) in
example (a b c : Nat) (h₁ : r b a) (h₂ : r b c) : r c a := by
apply?
-- now attach the `symm` attribute to `r.symm`
attribute [symm] r.symm
/--
info: Try this:
[apply] exact r.trans (id (r.symm h₂)) h₁
-/
#guard_msgs in
example (a b c : Nat) (h₁ : r b a) (h₂ : r b c) : r c a := by
apply?