大乘百法明門論開宗義決 1.191

1.191

彼令易解此令易緣者。解謂行解。行解轉易。緣謂所緣。所緣改變。由是於中四句分別。一易解不易緣。先計色常後計色斷。二易緣不易解。先計色常後計受常。三解緣俱易。先計色常後計受斷。四解緣俱不易。前念後念計色常等。

"That causes easy understanding; this causes easy objective support": "understanding" refers to mental grasp, the change of mental grasp; "objective support" refers to what is taken as an object, the modification of what is taken as an object. From this, there is a four-clause analysis: (1) easy understanding but not easy objective support, such as first calculating form as permanent and later calculating form as annihilated; (2) easy objective support but not easy understanding, such as first calculating form as permanent and later calculating sensation as permanent; (3) both understanding and objective support are easy, such as first calculating form as permanent and later calculating sensation as annihilated; (4) neither understanding nor objective support is easy, such as calculating form as permanent in both the previous and subsequent thought-moments.