This PR fixes a bug where `grind [foo]` fails when the theorem `foo` has
a different universe variable name than the goal, even though universe
polymorphism should allow the universes to unify.
The issue was in `instantiateGroundTheorem` (used for theorems with no
quantified parameters), which was passing `thm.proof` directly instead
of calling `getProofWithFreshMVarLevels`. This meant ground theorems
retained their original universe level params instead of getting fresh
level metavariables that could unify with the goal's universe levels.
Fixes
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/grind.20fails.20because.20of.20universe.20variable.20name🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
642bcdf55a