overlays-in
overlays-in is a built-in function in `C source code
'.
(overlays-in BEG END)
Return a list of the overlays that overlap the region BEG ... END.
Overlap means that at least one character is contained within the overlay
and also contained within the specified region.
Empty overlays are included in the result if they are located at BEG,
between BEG and END, or at END provided END denotes the position at the
end of the buffer.