In place of every proposition “p”, let us write “
a
b
p”. Let every correlation of propositions to each other or of names to propositions be effected by a correlation of their poles “a” and “b”. Let this correlation be transitive. Then accordingly “
a ‒ a
b ‒ b
p” is the same symbol as “
a
b
p”. Let n propositions be given. I then call a “class of poles” of these propositions every class of n members, of which each is a pole of one of the n propositions, so that one member corresponds to each proposition. I then correlate with each class of poles one of two poles (a and b). The sense of the symbolizing fact thus constructed I cannot define, but I know it.