This PR renames `instance_reducible` to `implicit_reducible` and adds a
new
`backward.isDefEq.implicitBump` option to prepare for treating all
implicit
arguments uniformly during definitional equality checking.
## Changes
**Rename `instance_reducible` → `implicit_reducible`:**
- Rename `ReducibilityStatus.instanceReducible` constructor to
`implicitReducible`
- Register new `[implicit_reducible]` attribute, keep
`[instance_reducible]` as alias
- Rename `isInstanceReducible` → `isImplicitReducible` (with deprecated
aliases)
- Update all references across src/ and tests/
The rename reflects that this reducibility level is used not just for
instances
but for any definition that needs unfolding during implicit argument
resolution
(e.g., `Nat.add`, `Array.size`).
**Add `backward.isDefEq.implicitBump` option:**
- When `true` (+ `respectTransparency`), bumps transparency to
`.instances` for
ALL implicit arguments in `isDefEqArgs`, not just instance-implicit ones
- Defaults to `false` for staging compatibility — will be flipped to
`true` after
stage0 update
- Adds `// update me!` to `stage0/src/stdlib_flags.h` to trigger CI
stage0 update
## Follow-up (after stage0 update)
- Flip `backward.isDefEq.implicitBump` default to `true`
- Fix resulting test/module failures
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
