In the Excel table below, the 1^st column is the category and the 2^nd column contains detail data whose values are true or false.

Task: Find the category whose detail data does not have the true value. The expected result will be Andy and Tim.

Use SPL XLL to get this done:

=spl("=?.groups(~1;count(~2)).select(#2==0).(#1)",A1:B6)

groups() function groups and summarizes data; ~1 represents the 1^st child member of the current member; #1 is the 1^st column of the table.

Source:https://www.reddit.com/r/excel/comments/1cjcgcl/how_to_compare_two_columns_list_of_duplicate/