範疇文法
the N P / N , bad N / N , boy N , made ( N P ∖ S ) / N P , that N P / N , mess N {\displaystyle {{\text{the}} \atop {NP/N,}}{{\text{bad}} \atop {N/N,}}{{\text{boy}} \atop {N,}}{{\text{made}} \atop {(NP\backslash S)/NP,}}{{\text{that}} \atop {NP/N,}}{{\text{mess}} \atop {N}}}
そしてこれらに X ← X / Y , Y {\displaystyle X\leftarrow X/Y,\;Y} と X ← Y , Y ∖ X {\displaystyle X\leftarrow Y,\;Y\backslash X} の2つの規則を適用していくと,
. N P / N , N / N , N , ( N P ∖ S ) / N P , N P / N , N ⏟ {\displaystyle .\qquad NP/N,\;N/N,\;N,\;(NP\backslash S)/NP,\;\underbrace {NP/N,\;N} } . N P / N , N / N , N , ( N P ∖ S ) / N P , N P ⏟ {\displaystyle .\qquad NP/N,\;N/N,\;N,\;\underbrace {(NP\backslash S)/NP,\quad NP} } . N P / N , N / N , N ⏟ , ( N P ∖ S ) {\displaystyle .\qquad NP/N,\;\underbrace {N/N,\;N} ,\qquad (NP\backslash S)} .