diff --git a/README.md b/README.md
index 3303f98..512b4ee 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,7 @@ See the [manual](https://github.com/Leedehai/typst-physics/blob/master/physica-m
 
 A larger [demo.typ](https://github.com/Leedehai/typst-physics/blob/master/demo.typ):
 
-![demo-larger](https://github.com/Leedehai/typst-physics/assets/18319900/b7dadf90-b401-4bbb-aff7-7c8840954209)
+![demo-larger](https://github.com/Leedehai/typst-physics/assets/18319900/75b94ef8-cc98-434f-be5f-bfac1ef6aef9)
 
 ## Using physica in your Typst document
 
diff --git a/physica-manual.pdf b/physica-manual.pdf
index feaa1af..fd4612a 100644
Binary files a/physica-manual.pdf and b/physica-manual.pdf differ
diff --git a/physica-manual.typ b/physica-manual.typ
index a9b9f46..bacc566 100644
--- a/physica-manual.typ
+++ b/physica-manual.typ
@@ -591,11 +591,12 @@ Functions: `differential(`\*_args_, \*\*_kwargs_`)`, abbreviated as `dd(`...`)`.
 - named _kwargs_:
   - `d`: the differential symbol [default: `upright(d)`].
   - `p`: the product symbol connecting the components [default: `none`].
+  - `compact`: only effective if `p` is `none`. If `#true`, will remove the TeXBook-advised thin spaces between the d-units [default: `#false`].
 
 TeXBook advises _[f]ormulas involving calculus look best when an extra thin space
 appears before dx or dy or d whatever_ (Chapter 18 p.168), and this package
-heeds this advice. If you don't want the spaces between the d-units, you may set
-in a `compact:#true` argument: $dd(r,theta) "vs." dd(r,theta,compact:#true)$ (compact).
+heeds this advice. If you don't want the spaces between the d-units, you may
+pass a `compact:#true` argument: $dd(r,theta) "vs." dd(r,theta,compact:#true)$ (compact).
 // https://github.com/typst/typst/issues/147 advocates for set rules for
 // non built-in functions. When that's implemented, user can do a
 // #set dd(compact: true) to set this param for all dd() invocations.