This PR adds `simplifying_assumptions [Nat.add_assoc]` to the
`vcgen_get_throw_set_grind` benchmark, recovering hypothesis
simplification lost in a54eafb ("refactor: decouple solve from grind").
That refactor introduced `PreTac.processHypotheses` which wraps
`simpNewHyps`, but the call sites in `work` and `main` call
`Grind.processHypotheses` directly, leaving `simpNewHyps` as dead code.
Without it, long `s + 1 + … + 1` chains are never collapsed, causing an
asymptotic slowdown visible by a factor of 2 at n=150 (largest radar
input size).
Benchmark results (VCGen time in ms):
| n | Before | After | Speedup |
|---|--------|-------|---------|
| 50 | 222 | 186 | 1.2× |
| 100 | 391 | 251 | 1.6× |
| 150 | 647 | 329 | 2.0× |
| 200 | 995 | 415 | 2.4× |
| 300 | 1894 | 589 | 3.2× |
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
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