diff --git a/macros.typ b/macros.typ
new file mode 100644
index 0000000..54b160c
--- /dev/null
+++ b/macros.typ
@@ -0,0 +1,23 @@
+#let Skylighting(fill: none, number: false, start: 1, sourcelines) = {
+   let blocks = []
+   let lnum = start - 1
+   let bgcolor = rgb("#f1f3f5")
+   for ln in sourcelines {
+     if number {
+       lnum = lnum + 1
+       blocks = blocks + box(width: if start + sourcelines.len() > 999 { 30pt } else { 24pt }, text(fill: rgb("#aaaaaa"), [ #lnum ]))
+     }
+     blocks = blocks + ln + EndLine()
+   }
+   block(fill: bgcolor, width:100%, inset:(x:5pt, y:8pt), stroke:( left: 2pt + green), below:0pt, blocks)
+}
+
+
+#set math.mat(delim: "[")
+
+// now in index.qmd 
+//#set math.equation(numbering: none)
+// not enough
+//#let equation-numbering = it => {
+//  numbering(none, it)
+//}
\ No newline at end of file