diff --git a/pythonetc/README.md b/pythonetc/README.md
index 6d62f77..ee0d233 100644
--- a/pythonetc/README.md
+++ b/pythonetc/README.md
@@ -95,6 +95,7 @@ More:
 1. ./dedent.md
 1. ./immutable.md
 1. ./sqlite3.md
+1. ./str-chain.md
 
 Out of order:
 
diff --git a/pythonetc/str-chain.md b/pythonetc/str-chain.md
new file mode 100644
index 0000000..2108ec5
--- /dev/null
+++ b/pythonetc/str-chain.md
@@ -0,0 +1,15 @@
+Since Python doesn't have a `char` type, an element of `str` is always `str`:
+
+```python
+'@pythonetc'[0][0][0][0][0]
+# '@'
+```
+
+This is an infinite type and you can't construct in a strictly typed language (and why would you?) because it's unclear how to construct the first instance ([thing-in-itself](https://en.wikipedia.org/wiki/Thing-in-itself)?). For example, in Haskell:
+
+```haskell
+Prelude> str = str str
+
+:1:7: error:
+    • Occurs check: cannot construct the infinite type: t1 ~ t -> t1
+```