diff --git a/dsl/README.md b/dsl/README.md
index a5bcf22..6220947 100644
--- a/dsl/README.md
+++ b/dsl/README.md
@@ -113,3 +113,13 @@ this is the trait which differentiates "a thing" from
 * e1: Unexpected '('
 * e2: Unexpected 'b'
 * e3: Unexpected 'd'
+
+## todo
+
+### operators
+
+* replace: `(:= :name :value1 :valueN)`
+* append:  `(:+ :name :value2 :valueN)`
+* filter:  `(:- :name :value2 :valueN)`
+* map:     `(:* :name op)`
+* reduce:  `(:/ :name op)`