(7) A state that assists by means of mutual arousing and consolidating is a mutuality condition, as the three sticks of a tripod give each other consolidating support. With the immaterial aggregates, etc., it is threefold, according as it is said: 'The four immaterial aggregates are a condition, as mutuality condition, [for each other]; the four great primaries are a condition, as mutuality condition, [for each other]; at the moment of descent into the womb mentality and materiality are a condition, as mutuality condition, [for each other]' (Ptn.1,3).