Fire is related to Light. Light is a type of Condition. Condition is a type of Illness. 
Appoint is related to Selection. Selection is related to Song. Song is a type of Poem. Poem can be used for Reading. 
Fire <--RelatedTo--> Light --IsA--> Condition --IsA--> Illness 
Appoint <--RelatedTo--> Selection <--RelatedTo--> Song --IsA--> Poem --UsedFor--> Reading 