Anybody helps me, please.

maybe at mod/messageboard/actions/add.php add :

add_new_notification($owner_guid, elgg_get_logged_in_user_entity(), $action_type, $entity_guid, $message_content);

after line 16, but for $action_type and $entity_guid, I have no idea what the value should be~

Hi Bill,

it is really a long time since you asked about math formulas in TinyMCE. 

You can have a look into WIRIS math editor, a WYSIYWG tool to edit equation editors with a Javascript interface. 

www.wiris.com/editor/demo

You can use it in TinyMCC and also in CKeditor

www.wiris.com/solutions/tinymce

www.wiris.com/solutions/ckeditor