This is the foundation of ideometry. From this basis we can go on to construct systematic philosophy or basic science and its enjoyment and appreciation. Doing so amounts to systematic metaphysics, or, in a word, ideometry . There is a successor to expression just as there is a successor to the number four. The successor to expression is understanding expression possible without understanding, but no understanding without expression, and no consequence of expression except as there is understanding.
Understanding occurs when there is the sum, expression plus life.
For example it happens when one opens a book and lends oneself to it by reading. If one can not do that, or somehow does not, there is not understanding, though the book is still expression and one is still living. Similarly there can be the numbers four and one without their sum, five. Various positional systems of abbreviating the expression of numbers are possible, binary being the simplest, including octal, decimal, and hexadecimal to name some in conventional use. The base of the quinary system so expressed, which may be called ideo-quinary , is as always the second numeral followed by the first, grouped in succession without a space or other punctuation mark, as in 10, thus, lu .