 The expression \(UN(\textsf{B}(UP)(\textsf{C}G))\) may look “unfamiliar” when compared to formulas of FOL, but notation—to a large extent—is a matter of convention. It may be interesting to note that the first \(U\) is simply followed by its two arguments, however, the second \(U\) is not. \(\textsf{B}(UP)\) is a subexpression, but \(UP(\textsf{C}G)\) is not a subexpressions of \(UN (\textsf{B}(UP)(\textsf{C}G))\).  Furthermore, the whole expression can be transformed into \(XNPG\) using combinators, where \(X\) is composed of \(U\)s and combinators only. Such an \(X\) concisely encodes the logical form or logical content of the formula with the predicates being arguments.[5]