I worked on arch detection. I can't say its operational yet, but I fixed a possible bug with detecting the nearest crossings to a pair and better responded to the situation in which crossings decrease (now I atleast return the next best list of pairs instead of a list that is completely thrown off because of the less crossings. I also worked on detecting cases in which gaussians are very close together, so their outer zero crossings show first and get detected as 1 gaussian, instead of wings of separate wings. Now, as the inner points appears, the algorithm knows how to split the pairs such the gaussians are labeled correctly.