Implement is related to Pencil. Pencil is related to Instrument. Instrument is related to Mechanical. 
Obligation is a type of State. Obligation is related to Debt. Debt is related to Liability. Liability is a synonym of Commitment. 
Implement <--RelatedTo--> Pencil <--RelatedTo--> Instrument <--RelatedTo--> Mechanical 
State <--IsA-- Obligation <--RelatedTo--> Debt <--RelatedTo--> Liability <--Synonym--> Commitment 