As I know, "in/at which" can be replaced with "where" if the antecedent is referring to "place".<br/><br/>However, in this sentence<br/><br/> He published his second mathematics paper, in which he gave the<br/> modern definition ~.<br/><br/>I think the antecedent is not "place", so I wonder if the relative adverb "where" can replace "in which".