Contrary to what was written and implied, THERE IS NO AMBIGUITY IN THE OUTPUT OF THE U ELEMENT. For a given f(v,Z,t), the output of a u(f(v,Z,t)) operation will return an output which is unity when the argument is greater than zero, and zero otherwise. This may be seen from examination of the test circuit of part 1 of this article.

There may be a seeming ambiguity in some logical operations using 'u' expressions. If two or more 'u' expressions are summed, the output is NOT a logical OR of the two 'u' expressions but an arithmetic sum of the values of the 'u' expressions. Consequently, given functions f(a), f(b), ….f(z) where it is desired to get an output when any of these functions are greater than zero, it must be recognized that in this case one might get 26 different levels from the sum of the 'u' values for each expression.. Each non-zero level could represent different combinations of individual 'u' expressions. Consequently, in every case where 'u' expressions are summed to get a logical 'OR' output, an outer 'u' of this sum must be performed in order to get a unity multiplier for some output value.

Where 'u' expressions are multiplied, any single zero 'u' expression over an interval will 'blank' the overall product during that interval, and the overall product will be unity or zero, consequently a product of individual 'u' expressions (where these inner products are themselves corrected if they are the result sums of 'u' expressions) will be correct.

An Aside:

This correction became apparent when I was looking into the possibility of incorporating majority logic expressions into a simulation. Basically majority logic assigns differing logical 'weights' to differing gate inputs. When a majority 'weight' is present the gate will switch.

This was implemented by a simple sum of 'u' expressions which each were multiplied the appropriate 'weight'. The sum of these expressions was compared to a majority value in an outer 'u' sum of the individual terms.