It seems at first sight as if the a–b notation must be wrong, because it seems to treat true & false as on exactly the same level. It must be possible to see from the symbols themselves that there is some essential difference between the poles, if the notation is to be right; & it seems as if in fact this was impossible. [True]
     How asymmetry is introduced is by giving a description of a particular form of symbol which we call a ‘tautology’. The description of the a–b symbol alone is symmetrical with respect to a & b; but this description & the fact that what satisfies the description of the || a tautology is a tautology is asymmetrical with regard to them. (To say that a description was symmetrical with regard to 2 symbols, would mean that || we could substitute one for the other, & yet the description remain the same, i.e. mean the same.)