User blog comment:Ikosarakt1/Formal definition of tetrational arrays/@comment-5529393-20130329075222/@comment-5529393-20130331112051

Unfortunately, you still need a rule that explains what you do with exponents. Rule A7 doesn't help - sure, it sets B to X^2, but it doesn't say what you do with B. The rule that X^2 becomes X*p only applies to the original structure.