/ab/
How about squab?
START |s q u a b a |s q u a b Nope START s|q u a b a s|q u a b Nope START s q|u a b a s q|u a b Nope START s q u|a b a s q u|a b Yes! b s q u<a|b Yes! END s q u<a b> Yes!
We reached END, so the match succeeds; it found the ab part of squab