1 files changed, 22 insertions, 0 deletions
diff --git a/tetris/utility.prn b/tetris/utility.prn
new file mode 100644
index 0000000..ca68dfe
--- /dev/null
+++ b/tetris/utility.prn
@@ -0,0 +1,22 @@
+@defun "diff2" {
+	"y2" store
+	"x2" store
+	"y1" store
+	"x1" store
+	x1 x2 -
+	y1 y2 -
+}
+
+@defun "dup2" {
+	"b" store
+	"a" store
+	a b a b
+}
+
+@defun "swap2" {
+	"b2" store
+	"b1" store
+	"a2" store
+	"a1" store
+	b1 b2 a1 a2
+}