Method try_get_expr

crates/kernel/src/env.rs:95–97

(&self, hash: &blake3::Hash)

/// uniqueness per shallow structural key within that environment:
/// `ptr(a) == ptr(b)` iff `key(a) == key(b)` for interned values.
///
/// Also owns reusable scratch buffers used by `subst`, `simul_subst`, and
/// `lift` to memoize content-addressed sub-traversals within a single
/// call. Allocating these as `FxHashMap::default()` per call shows up in
/// profiles for big mathlib blocks where beta/zeta reductions fire
/// millions of times; threading the scratch through the `&mut InternTable`