Structured data can be imported to graph databases like Apache Jena or RDFox, and then recursive queries can be done with alternatives. Here is an example usin

Structured data can be imported to graph databases like Apache Jena or RDFox, and then recursive queries can be done with alternatives. Here is an example using RDFox: https://imgur.com/ziZdIzA https://imgur.com/ziZdIzA My fridge has "noodles, tomatos and butter", But I know only one recipe which calls for "noodles, sauce, oil, optionally cheese". However you put alternatives in the database, if you have tomatos, you can make sauce, if you have butter, you don't need oil. RDFox correctly says I can still make :spaghetti. Query: select DISTINCT ?recipe where { :fridge :item ?x. ?recipe a :recipe. ?recipe :requires ?y. OPTIONAL { ?y :alternative ?z }. FILTER(?x IN (?y, ?z)) }