Examples

The symbols $\varnothing$, $\mathbf{N}$, “the real line”, “the $\Gamma$ function”, $f\circ g$ represent terms. The symbols $\pi=\sqrt{2}+\sqrt{3}$, $1\in2$, “every finite division ring is a field”, “the zeros of $\zeta(s)$ other than $-2$, $-4$, $-6$, ... lie on the line $\mathfrak{R}(s)=1/2$” represent relations. The symbol “3 and 4” represents neither a term nor a relation.

The initial sign of a relation is $\vee$, $\neg$, or a relational sign. The initial sign of a term is either $\tau$ or a substantific sign, provided that the term does not consist of a single letter. The latter assertion follows from the fact that a term is an assembly of the first species. If $A$ is a relation, then $A$ features in a formative construction, is not a letter, and does not begin with $\tau$, so that three cases are possible : (1) $A$ is preceded by an assembly $B$ such that $A$ is $\neg B$; (2) $A$ is preceded by two assemblies $B$ and $C$ such that $A$ is $\vee BC$; (3) $A$ is preceded by assemblies $A_1$, $A_2$, ... $A_n$ such that $A$ is $sA_1A_2 ... A_n$, $s$ being a relational sign.