user: Question: Who was performer 4 when Kate Robbins was performer 3?
Columns: ['Date', 'Episode', 'Performer 1', 'Performer 2', 'Performer 3', 'Performer 4']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['2 January 1988', 1.0, 'John Sessions', 'Stephen Fry', 'Dawn French', 'Lenny Henry']
SQL:

assistant: SELECT "Performer 4" FROM "Table" WHERE "Performer 3" = 'Kate Robbins';