diff --git a/crates/query-ops/README.md b/crates/query-ops/README.md
index 3a52b0c..021e7ef 100644
--- a/crates/query-ops/README.md
+++ b/crates/query-ops/README.md
@@ -5,20 +5,22 @@ The operators are: atom scan, semijoin, and natural join.
 
 ### Public API
 
-| Item                                             | Type     | Description                                                                                                                                                                                                         |
-|--------------------------------------------------|----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Item                                             | Kind    | Description                                                                                                                                                                                                         |
+|--------------------------------------------------|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `scan_atom(&Table, &AtomPattern) -> Relation`    | function | Scans the table under the pattern and returns a binding relation with one column per distinct variable in first-occurrence order. Literal positions and repeated variables filter rows during the scan.             |
 | `semijoin(&Relation, &Relation) -> Relation`     | function | Returns the rows of `left` whose values on the columns shared with `right` also appear in `right`. The output column list is the same as `left.columns`.                                                            |
 | `natural_join(&Relation, &Relation) -> Relation` | function | Returns every pair of `left` and `right` rows that agree on shared columns. Each output row holds the columns of `left` followed by the non-shared columns of `right`.                                              |
-| `Table`                                          | struct   | Holds positional input rows of fixed arity and carries no column names. Construct it with `Table::new(arity)` or `Table::from_rows(arity, rows)`.                                                                   |
-| `AtomPattern`                                    | struct   | Specifies, for each table column, either a variable to bind or a literal value to match. The pattern is a `Vec<Term>` whose length must equal the table's arity.                                                    |
-| `Term`                                           | enum     | Represents one position of an `AtomPattern`. A term is either `Var(String)` to bind the cell to a named variable, or `Lit(Value)` to require the cell to equal a given value.                                       |
-| `Relation`                                       | struct   | Holds rows over named columns and is the type produced by every operator. Construct it with `Relation::new(columns)` or `Relation::from_rows(columns, rows)`. Column names within a single relation must be unique. |
-| `Value`                                          | enum     | Represents a single cell value stored in a `Table` or `Relation`. A value is either `Int(i64)` or `Str(String)`.                                                                                                    |
+| `Table`                                          | struct  | Holds positional input rows of fixed arity and carries no column names. Construct it with `Table::new(arity)` or `Table::from_rows(arity, rows)`.                                                                   |
+| `AtomPattern`                                    | struct  | Specifies, for each table column, either a variable to bind or a literal value to match. The pattern is a `Vec<Term>` whose length must equal the table's arity.                                                    |
+| `Term`                                           | enum    | Represents one position of an `AtomPattern`. A term is either `Var(String)` to bind the cell to a named variable, or `Lit(Value)` to require the cell to equal a given value.                                       |
+| `Relation`                                       | struct  | Holds rows over named columns and is the type produced by every operator. Construct it with `Relation::new(columns)` or `Relation::from_rows(columns, rows)`. Column names within a single relation must be unique. |
+| `Value`                                          | enum    | Represents a single cell value stored in a `Table` or `Relation`. A value is either `Int(i64)` or `Str(String)`.                                                                                                    |
+
+Data types and their relationships:
 
 <div align="center">
   <picture>
-    <img alt="Types" src="docs/diagrams/types.svg" height="50%" width="50%">
+    <img alt="Types" src="docs/diagrams/types.svg" height="60%" width="60%">
   </picture>
 </div>
 
@@ -30,7 +32,7 @@ It uses all three operators:
 - `semijoin` to keep only authors of bestsellers,
 - and `natural_join` to attach each book's price.
 
-```text
+```prolog
 Q(name, book, dollars) :- author(name, book), bestseller(book), price(book, dollars).
 ```