diff --git a/context/adr/009-incremental-evaluation.md b/context/adr/009-incremental-evaluation.md
index 68135713..70d4b155 100644
--- a/context/adr/009-incremental-evaluation.md
+++ b/context/adr/009-incremental-evaluation.md
@@ -51,10 +51,12 @@ formula, so there is no second query language.
 
 ### 2. The plug
 
-improvise-core gains a trait, `Derived`, for the two things the evaluator reads: the
-formula result at a key, and the raw fold of the cells that match a partial key. The
-incremental backend implements it in a seam crate, `improvise-incremental`, which
-depends on `zset` and improvise-core. improvise-core never depends on `zset`.
+The seam crate `improvise-incremental` holds a trait, `Derived`, for the two things the
+evaluator reads: the formula result at a key, and the raw fold of the cells that match a
+partial key. `Eager` lives beside it in that crate. The incremental backend implements
+`Derived` there too. `improvise-incremental` depends on improvise-core, and later on
+`zset`. improvise-core defines no `Derived` and never depends on `zset` or on
+`improvise-incremental`.
 
 A live source (ADR 003) that reports its changes feeds cell deltas like `DataStore`. A
 source that answers aggregate queries but reports no changes implements the derived-value
@@ -63,7 +65,7 @@ operator directly, by query pushdown, with no change feed.
 The circuit decides *which* formula cells to re-evaluate. The one existing evaluator
 computes each value, so formulas are never compiled into operators.
 
-**`Eager` is temporary.** Today's code moves behind the trait as `Eager`, unchanged. It
+**`Eager` is temporary.** Today's code is wrapped behind the trait as `Eager`, unchanged. It
 exists only to show discrepancies between the new evaluator and the old one: a
 differential property test applies one random edit sequence to both backends and
 compares every drawn cell, total and occupancy count. Eventually it is deleted, and