@dselsam The method `try_user_congr` was leaking a temporary
meta-variable into the formula. The problem in the congruence lemma
```
dif_ctx_simp_congr :
∀ {α : Sort u_1} {b c : Prop} [dec_b : decidable b] {x : b → α} {u : c → α} {y : ¬b → α} {v : ¬c → α}
(h_c : b ↔ c),
(∀ (h : c), x (h_c.mpr h) = u h) →
(∀ (h : ¬c), y ((not_iff_not_of_iff h_c).mpr h) = v h) → dite b x y = dite c u v
```
when the hypothesis `(∀ (h : c), x (h_c.mpr h) = u h)` is processed,
`h_c` is still unassigned. `h_c` was being assigned in a second
loop (the one that I deleted). Do you see any reason for having this
second pass? I think it is an optimization, we can skip the potentially
expensive
```
expr hyp = finalize(m_ctx, rel, r_congr_hyp).get_proof();
expr pf = local_factory.mk_lambda(hyp);
```
if the expression has not been simplified.
Anyway, I removed this code and merged both loops.
I don't think it should impact performance since we barely use custom
congruence lemmas.
Before this commit, simp would not silently apply refl-lemmas, and use
reflexivity. This strategy produces compact proofs but may generate
performance problems. For example, the new test timeouts without this
commit.
I believe a similar performance problem is affecting the Certigrad
project developed by @dselsam.
@kha I'm not sure if this is the right fix. I just avoided the loop that adds
`mk_expr_placeholder` if the function is not a projection.
I didn't spend time investigating why we need `mk_proj_app`.
I know the library doesn't compile if we don't use it, and just use
```
return mk_app(copy_tag(ref, mk_constant(S_name + fname)), e);
```
:)
Holes {! ... !} are elaborated using `sorry`.
We report an error if their value is fixed by typing and/or
elaboration rules.
We store the tactic_state and the optional attribute in the
info_manager. The idea is to allow users to execute commands with
respect to the stored tactic state and optional attribute.
The optional attribute is a pre term.
We are planning to add commands such as:
- Check type of the given argument.
- Reduce the given argument.
- Synthesize the hole automatically, where the given argument encodes
hint to the synthesizer.
- Use the given argument to fill the hole.
This feature is needed when we declare an inductive predicate/type
which is indexed by a mutual and/or nested inductive datatype.
See tests/lean/run/term_pred.lean for an example.
@Armael: this commit should fix the issue with the `cases` tactic that
you reported today.
We want to make sure string users do not depend on the string
implementation. This is the first step.
We need this refactoring *now* to make sure it will not be
super painful to address issue #1175
@Armael: the new file `tests/lean/run/add_interactive.lean` contains a
small example. Note that we don't have auto quotation for commands yet.
So, I have to use the backtick in the example.
@Kha: this is a good candidate for the future command parser extensions.
They can be used to store user state in the tactic_state object.
@Armael @jroesch: The new file tests/lean/run/tactic_ref.lean contains a few examples.
