 To determine what a given term “Xi” means, we find the kind Ki that is most effective at causing “Xi”. This can be computed from S’s biography. For each Ki and “Xi”, we compute the frequency with which Ki triggers “Xi”. “X1” is tokened four out of six times that K1 is encountered, three out of three times that K2 is encountered, and one out of four times that K3 is encountered. “Xi” means that Ki that has the highest sample frequency. Thus, in this case, “X1” means K2. Just to be clear, when BTT claims that “Xi” means the Ki that is the most powerful stimulant of “X”, this is not to say that “X” means the most common stimulant of “X”. In our spreadsheet biography, K1 is the most common stimulant of “X1”, since it triggers “X1” four times, where K2 triggers it only three times, and K3 triggers it only one time. This is why, according to BTT, “X1” means K2, rather than K1 or K3.