can you make sure there are cross$-$cutting implications by putting unidirectional arrows on it to show the directions of implication. I$\text{'}$m supposed to create a graph of "ontology" that contains at least $20$ entities or classes and has at least $3$ levels in it somewhere. Your graph should also have at least one cross$-$categorization that cuts across the other hierarchy$(-$ies. In your ontology graph, it's important that any arrow from concept A to concept B on the graph has the relation $"$if A then B$"$ and not just an association between the two. Make sure that you are not drawing lines between concepts that have associations rather than implications. For example, $"$if popcorn then food" is a valid implication because popcorn is a type of food but "popcorn $--$ movie theatre" is not a valid implication in either direction. Popcorn is not a type of movie theatre and movie theatres are not a type of popcorn. That is an association rather than an implication since one might associate popcorn with movie theatres. There also need to be places in your graph where concept A points to both B and C but there is no line between B and C$.$ This will happen when you have some cross$-$cutting concepts.