digraph g {
"context" -> "semantic network example"
"Mammal" -> "Vertebra" [label="has",arrowhead=normal]
"Mammal" -> "Animal" [label="is-an",arrowhead=normal]
"Cat" -> "Mammal" [label="is-a",arrowhead=normal]
"Cat" -> "Fur" [label="has",arrowhead=normal]
"Bear" -> "Mammal" [label="is-a",arrowhead=normal]
"Bear" -> "Fur" [label="has",arrowhead=normal]
"Whale" -> "Mammal" [label="is-a",arrowhead=normal]
"Whale" -> "Water" [label="lives-in",arrowhead=normal]
"Fish" -> "Animal" [label="is-an",arrowhead=normal]
"Fish" -> "Water" [label="lives-in",arrowhead=normal]
}