user: Question: What is the System when the Licence is GPL and the Current Version is 1.72?
Columns: ['Name', 'Current version', 'System', 'Platform', 'License']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Atari800', '3.0.0', 'Atari 5200 , various Atari 8-bit computers', 'Cross-platform', 'GPL']
SQL:

assistant: SELECT "System" FROM "Table" WHERE "License" = 'GPL' AND "Current version" = '1.72';