diff --git a/crates/query-ops/README.md b/crates/query-ops/README.md
index edcd325..583cc52 100644
--- a/crates/query-ops/README.md
+++ b/crates/query-ops/README.md
@@ -34,9 +34,12 @@ It uses all three operators:
 - and `natural_join` to attach each book's price.
 
 ```prolog
+% Datalog rule/query
 Q(name, book, dollars) :- author(name, book), bestseller(book), price(book, dollars).
 ```
 
+The code below implements the rule (also available [here](tests/hand_plan.rs)):
+
 ```rust
 use query_ops::atom::{AtomPattern, Term, scan_atom};
 use query_ops::join::{natural_join, semijoin};
@@ -54,20 +57,26 @@ fn main() {
     let author = Table::from_rows(
         2,
         vec![
-            vec![s("Alice"), s("Foo")],
-            vec![s("Bob"), s("Bar")],
-            vec![s("Alice"), s("Baz")],
-            vec![s("Carol"), s("Qux")],
+            vec![s("Ursula K. Le Guin"), s("A Wizard of Earthsea")],
+            vec![s("Toni Morrison"), s("Beloved")],
+            vec![s("Ursula K. Le Guin"), s("The Left Hand of Darkness")],
+            vec![s("Terry Pratchett"), s("Mort")],
+        ],
+    );
+    let bestseller = Table::from_rows(
+        1,
+        vec![
+            vec![s("A Wizard of Earthsea")],
+            vec![s("The Left Hand of Darkness")],
         ],
     );
-    let bestseller = Table::from_rows(1, vec![vec![s("Foo")], vec![s("Baz")]]);
     let price = Table::from_rows(
         2,
         vec![
-            vec![s("Foo"), i(25)],
-            vec![s("Bar"), i(15)],
-            vec![s("Baz"), i(30)],
-            vec![s("Qux"), i(20)],
+            vec![s("A Wizard of Earthsea"), i(14)],
+            vec![s("Beloved"), i(17)],
+            vec![s("The Left Hand of Darkness"), i(15)],
+            vec![s("Mort"), i(12)],
         ],
     );
 
@@ -100,14 +109,14 @@ fn main() {
     assert_eq!(
         result.rows,
         vec![
-            vec![s("Alice"), s("Foo"), i(25)],
-            vec![s("Alice"), s("Baz"), i(30)],
+            vec![s("Ursula K. Le Guin"), s("A Wizard of Earthsea"), i(14)],
+            vec![s("Ursula K. Le Guin"), s("The Left Hand of Darkness"), i(15)],
         ],
     );
 }
 ```
 
-How it works:
+How it works (logically):
 
 <div align="center">
   <picture>
diff --git a/crates/query-ops/tests/hand_plan.rs b/crates/query-ops/tests/hand_plan.rs
index 7265610..f08b402 100644
--- a/crates/query-ops/tests/hand_plan.rs
+++ b/crates/query-ops/tests/hand_plan.rs
@@ -31,20 +31,26 @@ fn authors_of_bestsellers_with_price() {
     let author = Table::from_rows(
         2,
         vec![
-            vec![s("Alice"), s("Foo")],
-            vec![s("Bob"), s("Bar")],
-            vec![s("Alice"), s("Baz")],
-            vec![s("Carol"), s("Qux")],
+            vec![s("Ursula K. Le Guin"), s("A Wizard of Earthsea")],
+            vec![s("Toni Morrison"), s("Beloved")],
+            vec![s("Ursula K. Le Guin"), s("The Left Hand of Darkness")],
+            vec![s("Terry Pratchett"), s("Mort")],
+        ],
+    );
+    let bestseller = Table::from_rows(
+        1,
+        vec![
+            vec![s("A Wizard of Earthsea")],
+            vec![s("The Left Hand of Darkness")],
         ],
     );
-    let bestseller = Table::from_rows(1, vec![vec![s("Foo")], vec![s("Baz")]]);
     let price = Table::from_rows(
         2,
         vec![
-            vec![s("Foo"), i(25)],
-            vec![s("Bar"), i(15)],
-            vec![s("Baz"), i(30)],
-            vec![s("Qux"), i(20)],
+            vec![s("A Wizard of Earthsea"), i(14)],
+            vec![s("Beloved"), i(17)],
+            vec![s("The Left Hand of Darkness"), i(15)],
+            vec![s("Mort"), i(12)],
         ],
     );
 
@@ -84,8 +90,12 @@ fn authors_of_bestsellers_with_price() {
     assert_eq!(
         result.rows,
         vec![
-            vec![s("Alice"), s("Foo"), i(25)],
-            vec![s("Alice"), s("Baz"), i(30)],
+            vec![s("Ursula K. Le Guin"), s("A Wizard of Earthsea"), i(14)],
+            vec![
+                s("Ursula K. Le Guin"),
+                s("The Left Hand of Darkness"),
+                i(15)
+            ],
         ],
     );
 }