Advanced search functions for Google Inbox
Here’s a link to some advanced search functions for gmail and Google Inbox: https://support.google.com/mail/answer/7190?hl=en
Not mentioned in the page are some useful additions for use with Inbox:
1) You can negate a term by putting a – in front of the flag (e.g. -is:done
) means select messages that are not done.
2) You can use terms like “done” which are not listed in the page: after:2016/01/05 is:unread -is:done
selects all mail after January 5, 2016 that is unread and not marked as being done.