there was a check
if !Structural.recArgHasLooseBVarsAt recFnName fixedPrefixSize e then
that would avoid going through `.refineThrough`/`.addArg` for
matcher/casesOn applications. It seems it tries to detect when refining
the motive/param is pointless, but it was too eager, and cause confusion
with, for example, this reasonably reasonable function:
def foo : (n : Nat) → (i : Fin n) → Bool
| 0, _ => false
| 1, _ => false
| _+2, _ => foo 1 ⟨0, Nat.zero_lt_one⟩
decreasing_by simp_wf; simp_arith
In particular, the `GuessLex` code later expects that the (implict)
`PProd.casesOn` in the implementation of `foo._unary` will refine the
paramter, because else the (rather picky) `unpackArg` fails. But it also
prevents this from being provable.
So let's try without this shortcut.
Fixing this also revealed that `withRecApps` wasn’t looking in all
corners
of a matcherApp/casesOnApp.
Fixes#3175
this didn’t recognize the new comments with an intro, and thus the bot
would post multiple comments.
The code was also out of sync with mathlib, fixing.
The `first(…)` in the `jq` program makes it more robust in case this
went wrong once (as on #3171) and there are now multiple PRs matching.
This uses the improved termination_by syntax to give Nat.gcd a cleaner
definition. It removes the last explicit use of WellFounded.fix in Init.
This was also partly motivated by leanprover/std4#520 so that unfold
Nat.gcd gives a sensible definition.
If the current manifest is from unsupported (or has errors), a bare
`lake update` will now discard it and create a new one from scratch
rather than erroring and requiring you to manually delete the manifest.
Lake will produce warnings noting it is ignoring such invalid manifests.
so far, our reference manual did not mention these at all, this takes
the discussion of recursive definition out of the “equation compiler”
section, put it into its own section, and expands it a bit.
This is more a MVP doc change to at least mention the features briefly,
and not the most polished and thought through didactic exposition. But
it provides a start for more improvements.
---------
Co-authored-by: Arthur Adjedj <arthur.adjedj@gmail.com>
Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Co-authored-by: David Thrane Christiansen <david@davidchristiansen.dk>
This change
* moves `termination_by` and `decreasing_by` next to the function they
apply to
* simplify the syntax of `termination_by`
* apply the `decreasing_by` goal to all goals at once, for better
interactive use.
See the section in `RELEASES.md` for more details and migration advise.
This is a hard breaking change, requiring developers to touch every
`termination_by` in their code base. We decided to still do it as a
hard-breaking change, because supporting both old and new syntax at the
same time would be non-trivial, and not save that much. Moreover, this
requires changes to some metaprograms that developers might have
written, and supporting both syntaxes at the same time would make
_their_ migration harder.
This introduces `FilePath.addExtension` to take a path that we know has
no prior extension, and append a new extension to it.
As this function is simpler than `FilePath.withExtension`, this change
eagerly replaces uses of the latter with the former, except in a few
cases where stripping the extension really is the right thing to do.
This should fix the bug described at
https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Import.20file.20with.20multiple.20dots.20in.20file.20name/near/404508048,
where `import «A.B».«C.D.lean»` is needed to import `A.B/C.D.lean`.
Closes#2999
---------
Co-authored-by: Mac Malone <tydeu@hatpress.net>
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
To handle delaborating notations that are functions that can be applied
to arguments, extracts the core function application delaborator as a
separate function that accepts the number of arguments to process and a
delaborator to apply to the "head" of the expression.
Defines `withOverApp`, which has the same interface as the combinator of
the same name from std4, but it uses this core function application
delaborator.
Uses `withOverApp` to improve a number of application delaborators,
notably projections. This means Mathlib can stop using `pp_dot` for
structure fields that have function types.
Incidentally fixes `getParamKinds` to specialize default values to use
supplied arguments, which impacts how default arguments are delaborated.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
