Add typing syntax note in syntax doc
@@ -194,6 +194,12 @@ true
3
```
+The identifier in the `let` part can be typed (more about typing in the dedicated document):
+```
+> let a : Num = 6 in 6 * 7
+42
+```
+
## Functions
A function is declared using the `fun` keyword, then arguments separated by spaces, and finally an arrow `=>` to add the body of the function.
To call a function, just add the arguments after it separated with spaces.
