The rules for calculating truth functions are essentially algebraic in nature, and this is what allows their easy programming (as in the program PLN2 which you can use to find the truth value of any expression).

The following are algebraic equivalents for our familiar signals.
PN = P+1
PQA = PQ
PQO = PQ+P+Q
PQC = PQ+P+1
QPC = PQ+Q+1
PQB = P+Q+1
PQM = P+Q

A particular advantage of algebraic notation is that it provides unique formulas for every logical relationship. Consequently, another way of showing whether two strings are equivalent is to reduce each to its simplest algebraic equivalent and see if they are identical.

It should be noted that algebraic notation as used here is based on a mod-2 arithmetic and is not the same as Boolean algebra. The key distinction is that in Boolean algebra the rule is that 1+1=1 while in mod 2 arithmetic it is that 1+1=0.

You can experiment with the program Converting AN that will allow you to find the AN (algebraic notation) equivalents of PLN expressions and the PLN equivalents of AN expressions.

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