摩訶止觀 2.100

2.100

復次，但約最後善明隨自意，此是次第意。若善惡俱明隨自意，即是頓意。若約襵牒之善明隨自意，此則不定意（云云）。

Furthermore, explaining 'following one's own mind' solely in terms of ultimate wholesome [states] represents the gradual intention. Explaining 'following one's own mind' in terms of both wholesome and unwholesome represents the sudden intention. Explaining 'following one's own mind' in terms of folded and interleaved wholesome [states] represents the indeterminate intention (and so forth).