spec: fix two copy/paste errors (#107)
diff --git a/doc/spec.md b/doc/spec.md
index 3b5a3b4..870e9ec 100644
--- a/doc/spec.md
+++ b/doc/spec.md
@@ -3896,7 +3896,7 @@
<a id='string·title'></a>
### string·title
-`S.lower()` returns a copy of the string S with letters converted to titlecase.
+`S.title()` returns a copy of the string S with letters converted to titlecase.
Letters are converted to uppercase at the start of words, lowercase elsewhere.
@@ -3907,7 +3907,7 @@
<a id='string·upper'></a>
### string·upper
-`S.lower()` returns a copy of the string S with letters converted to lowercase.
+`S.upper()` returns a copy of the string S with letters converted to uppercase.
```python
"Hello, World!".upper() # "HELLO, WORLD!"
