Fourfold Effort/Application

(cattari sammā-padhāņāni, catvāri samyak-pradhāņāni, 四正勤）is

1. severing unwholesome things (akusala dhamma)
2. preventing unwholesome things to arise
3. starting new wholesome things (kusala dhamma)
4. stabilizing wholesome things (or karma).

The Fourfold Right Severing (cattari sammā-pahāņāni, catvāri samyak-prahāņāni, 四正断）is a misinterpretation or mis-representation, because there are 3) and 4) (starting and stabilizing good things/karma).