5.42 It is obvious that v [i.e. or], [if…then], etc. are not relations in the sense that right and left etc. are.

The possibility of the crosswise definition of the logical “primitive signs” of Frege and Russell shows already that these are not primitive signs, and much less still signs for relations.

And it is obvious that the “[if…then]” that we define by means of “~” and “v” is identical with that by which we define “v” with the help of “~”, and that this “v” is the same as the first, and so on.

We have inter-definable signs, in other words, which are functions or operations. None is primitive, since they are inter-definable, and none is a relation. Translation of the last sentence based on Wittgenstein’s suggestion, p. 61 of Letters to Ogden.