Tiny fixes
diff --git a/packages/selector/src/index.ts b/packages/selector/src/index.ts
index e0a5e48..c028836 100644
--- a/packages/selector/src/index.ts
+++ b/packages/selector/src/index.ts
@@ -44,7 +44,7 @@
 export function makeRefinable<
   // Any subtype of Selector can be made refinable; but note we limit the value
   // of refinedBy because it must also be accepted by matcherCreator.
-  TSelector extends Selector & { refinedBy: TSelector },
+  TSelector extends Selector & { refinedBy?: TSelector },
   TScope,
   // To enable refinement, the implementation’s Match object must be usable as a
   // Scope object itself.
diff --git a/packages/selector/src/text/seeker.ts b/packages/selector/src/text/seeker.ts
index b8246c6..b83de4c 100644
--- a/packages/selector/src/text/seeker.ts
+++ b/packages/selector/src/text/seeker.ts
@@ -332,7 +332,7 @@
           this.currentChunkPosition + this.currentChunk.data.length;
         if (endOfChunk <= target) {
           // The target is beyond the current chunk.
-          // (we use < not ≤: if the target is *at* the end of the chunk, possibly
+          // (we use ≤ not <: if the target is *at* the end of the chunk, possibly
           // because the current chunk is empty, we prefer to take the next chunk)
 
           const [data, nextChunk] = this._readToNextChunk();