diff --git a/eta.ml b/eta.ml
new file mode 100644
index 0000000..67f2fe0
--- /dev/null
+++ b/eta.ml
@@ -0,0 +1,4 @@
+let (>>=) a b x = a x + b x
+let id x = x
+let (&) = (@@)
+let f x = (|>) x & id >>= id
diff --git a/t/nan.ml b/t/nan.ml
new file mode 100644
index 0000000..c92190c
--- /dev/null
+++ b/t/nan.ml
@@ -0,0 +1,2 @@
+let nan =
+  float_of_bits 0x7F_F0_00_00_00_00_00_01L
diff --git a/unrelated/emacs.md b/unrelated/emacs.md
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index 0000000..c3f495e
--- /dev/null
+++ b/unrelated/emacs.md
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+# OCaml とは全く関係ない emacs テクメモ
+
+## Kill Ring
+
+`kill` した文字列一覧
+
+* `(popup-menu 'yank-menu)`
+* `anything-show-kill-ring` (requires `anything`)
+
+## `list-buffers` つまり `C-x C-b` の挙動が変った死ね
+
+予期したバッファレイアウトにならなくなったので死ぬ。そこで
+
+```
+(global-change-key (kbd "<backtab>") 'shell-round-visit-buffer)
+
+(defun good-old-list-buffers () 
+  (interactive)
+  (if (not (string-equal (buffer-name (current-buffer)) "*Buffer List*"))
+      (save-selected-window (buffer-menu-other-window))))
+(global-change-key (kbd "C-x C-b") 'good-old-list-buffers)
+```
+
+## Interesting functions
+
+### `(bounds-of-thing-at-point THING)`
+
+```
+(defun hogehogera ()
+   (interactive)
+   (let* ( (bds (bounds-of-thing-at-point 'filename))
+          (p1 (car bds))
+	  (p2 (cdr bds)) )
+	      (message "%d %d" p1 p2)))
+```