ProbabilisticNonprojectiveParser.compute_max_subtract_score(column_index, cycle_indexes)[source]

When updating scores the score of the highest-weighted incoming arc is subtracted upon collapse. This returns the correct amount to subtract from that edge.

Parameters:column_index (integer.) – A index representing the column of incoming arcs

to a particular node being updated :type cycle_indexes: A list of integers. :param cycle_indexes: Only arcs from cycle nodes are considered. This is a list of such nodes addresses.