瑜伽論記 5.10

5.10

此中四轉，當知二時顛倒等者，基師釋：四轉者，一、有漏三摩地趣進時顛倒；二、有漏定趣退時顛倒；三、有漏定正退失無倒；四、無漏定進時無倒，或初二於進謂退名為顛倒，初於有漏定進時謂退，後於無漏定進時謂退，故皆名倒。

Regarding 'in these four turnings, one should know that at two times there is inversion, etc.': Master Ji explains: as for the four turnings, 1. when advancing toward tainted samādhi, there is inversion; 2. when tainted absorption tends toward retrogradation, there is inversion; 3. when tainted absorption actually retrogrades and is lost, there is non-inversion; 4. when taintless absorption advances, there is non-inversion. Or, the first two, regarding advancement as retrogradation, are called inversions: first, regarding the advance of tainted absorption as retrogradation; second, regarding the advance of taintless absorption as retrogradation; thus both are called inversions.