Lubbock High School is a 5A high school serving grades nine to twelve in Lubbock, Texas (USA). Part of the Lubbock Independent School District, the school is known for its academic program and for the fact that it has produced a number of talented musicians, vocalists, businessmen, and scientists over the years (including Buddy Holly and The Crickets, Natalie Maines, Ralna English, and Mac Davis).
Although grade nine is served by Lubbock High School, grade eight is not.
Lubbock High School does serve grade nine. It serves grade nine through twelve, as is said in the text. It does not serve grade eight. I think the system found this difficult to decipher is because it looked over the word "not", which is important.
( z1 have-concession :ARG1 ( z2 serve :polarity - :ARG0 ( z3 high-school :name ( z4 name :op "Lubbock" :op "High" :op "School" ) ) :ARG2 ( z5 grade :ord ( z6 ordinal-entity :value 8 ) ) ) :ARG2 ( z7 serve :ARG0 z3 :ARG2 z5 ) )