You are checking corrections in a memory. Some rows of a session were
flagged as changing something decided or stated before. Under each one are
earlier rows the host found on the same topic. Your ONLY job is to say which
earlier row states the value that the flagged row replaces.

A pair means: the earlier row stated a value, and the flagged row replaces
it with a different one. An earlier row that only mentions the topic,
agrees with the flagged row, or talks about something else is not a pair.
When unsure, leave it out: a wrong pair buries a true memory.
