comparing sequences that contain more than one of the

A bit of a Friday challenge...

Is it possible to compare to sequences such that items in the sequence
are consumed after the comparison?

For example, I want to compare two words to see if one is a subset of the other.

"farmer" and "frame"

If you do:

string-to-codepoints('farmer')[not(. = string-to-codepoints('frame'))]

the result is empty because the two r's in farmer are both being
compared to the single r in frame.

Currently I've a got a recursive function that removes each letter
after a match, but I'm wondering if there's a one-liner or some other
set based approach?


thanks
-- 
Andrew Welch
http://andrewjwelch.com
Kernow: http://kernowforsaxon.sf.net/