Complex sentence: The demand for consumer goods depends chiefly on the income Y and may be written functionally as C d (Y) the subscript d indicates that we are looking at demand; the actual level of consumption C will be the same.
Split into simpler sentences: The demand for consumer goods depends chiefly on the income Y and may be written functionally as C d (Y). The subscript d indicates that we are looking at demand; the actual level of consumption C will be the same.