Function slice_search 

pub fn slice_search(
    hashes: &[String],
    flagged: &[bool],
    distribution: &[FloatType],
    part: usize,
    measure: usize,
) -> MeasureRelationship

Which measure of one place across the parts most likely corrects the flagged one there: music21’s MeasureSlice.runSliceSearch.

hashes is the rhythm of that measure in every part and flagged says whose is itself flagged, since a flagged measure corrects nothing; distribution is how often each part’s measures read like the flagged part’s, which is one row of ScoreCorrector::vertical_probability_dist. The likeliest is the first of those as likely, and a part that cannot correct counts as nothing at all.