Decimal Numbers for Checking Summability

Assume that our technology uses "black boxes" that may be described by a planar figure. (See Fig. 1.) Each "box" has a finite number of inputs ordered in the manner shown in Fig. 1, from top to bottom on the left-hand side of the "box," and one output coming out of the right-hand side of the "box." The output is some function of the input variables. For the purpose of our discussion, the variables may be continuous or discrete or of any nature whatsoever, and each "box" may have any number of inputs.