user: Question: Performer 1 of Greg Proops, and a Date of 25 August 1995 is what performer 4?
Columns: ['Date', 'Episode', 'Performer 1', 'Performer 2', 'Performer 3', 'Performer 4']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['28 July 1995', 1.0, 'Greg Proops', 'Colin Mochrie', 'Niall Ashdown', 'Ryan Stiles']
SQL:

assistant: SELECT "Performer 4" FROM "Table" WHERE "Performer 1" = 'Greg Proops' AND "Date" = '25 August 1995';