premise: Def Leppard are an English rock band formed in 1977 in Sheffield as part of the new wave of British heavy metal movement. The following is a complete list of all official members, session musicians, featured artists, touring musicians, and live guests of Def Leppard's career
hypothesis: Def Leppard are a hair metal band.
reason: "Hair metal" is a term usually used to refer to certain types of metal or rock with disdain, including Def Leppard. The system does not believe this to be correct nor incorrect because the statement is not concerned with the definition of hair metal.