问题 Earlier today I asked for help for building a database in prolog and how to search by parameters, and somebody came up with this: You can also add a list of terms to every processor, like: processor(pentium_g4400, [brand('intel'), family('pentium'), series('g4400'), clock(3.3), socket('lga1151'), ram('ddr4'), cores(2), threads(2)]). In that case you can query with: processor(Proc, Specs), member(family('pentium'), Specs). And it worked pretty well, but, the command "member" does not seem to