Roman Numerals (I, II, III) were cumbersome to use and only maintained a dominant role in arithmetic until 1202, when Leonardo Fibonacci in his work Liber Abaci, demonstrated that calculations with Hindu-Arabic numerals (1, 2, 3) were far more efficient. The lack of mental and written efficiency in the use of traditional PWR symbols may be because they are not icons. Therefore, these extremely abstract symbols cannot in writing visually depict the truth tables themselves, the simple geometric forms, the notational symmetry relations, and the isomorphic sets of interrelations inherent in logic. Conversely, the XLA symbols are iconographic and they possess a shape value. This enables complex logical operations to be performed through easy flips and rotations of the letter shape symbols themselves. By design, the letter shape of each X-stem Logic Alphabet symbol visually embodies and displays its individual underlying logic truth table. In other words, after the simple and exact truth table code in the deep structure of XLA has been learned, operations performed on the letter shape symbols are equivalent to logical operations acting on highly abbreviated sets of mini truth tables. Consequently, those using XLA never have the need to interrupt their calculations to check rows and columns of laid out truth tables. This basic and central advantage of XLA over PWR is often not fully recognized, even by practiced logicians. Nonetheless, systems of notation evolve and improve over time (e.g. Roman Numerals to the Decimal System and Imperial Units to the Metric System). In brief, XLA is described in two steps: (1) give the 16 binary connectives the right geometry, the right shape value anatomy; and (2) add the transformational physiology, namely, apply the algebra of simple symmetry groups to the 16 iconic letter shape symbols. Change comes with a whisper. This whisper presents a triple isomorphism. The mental operations are the same as the symmetry operations are the same as the logical operations. Said the other way around, the logical operations are the same as the symmetry operations are the same as the mental operations. Said again in a different order, the logical operations are the same as the mental operations are the same as the symmetry operations. Here we have a prime example of cognitive ergonomics at its best. The single act of performing any one automatically performs the other two. Whether or not the (PMZ) (XLA) system, or something similar to it, replaces the traditional PWR symbols remains to be seen.