Correct a join type.  Add additional description.
@@ -27,7 +27,7 @@ input files, adjusted for predefined name aliasing.
improve the performance of future processing steps by eliminating
unwanted edges (or nodes).
- * to perform a logical operation on two sets of edges or nodes.
+ * to perform a logical (set) operation on two sets of edges or nodes.
* intersection (inner join, defined below)
* union (outer join, defined below; also, [`kgtk cat`](https:../cat))
@@ -267,7 +267,8 @@ compact the additional columns after the join:
### Joining Node Files: Set Intersection
-Node files may be joined to perform a set intersection.
+Node files may be joined to perform a set intersection using the default
+join type (omit `--left-join` and `--right-join`).
Left input file:
@@ -283,7 +284,7 @@ Right input file:
| block1 |
| block3 |
-Output file after an inner join:
+Output file after the inner join:
| id |
| --- |
@@ -291,7 +292,8 @@ Output file after an inner join:
### Joining Node Files: Set Union
-Node files may be joined to perform a set union.
+Node files may be joined to perform a set union. Use `--left-join --right-join` to
+perform an outer join.
Left input file:
@@ -307,7 +309,7 @@ Right input file:
| block1 |
| block3 |
-Output file after an inner join:
+Output file after the outer join:
| id |
| --- |
