Valid is a synonym of Available. Available is related to Provide. Provide is a synonym of Contribute. Contribute is a synonym of Gift. 
Bridge is related to Walk. Walk is related to Motion. Pursuit is a type of Motion. Pursuit is derived from Pursue. 
Valid <--Synonym--> Available <--RelatedTo--> Provide <--Synonym--> Contribute <--Synonym--> Gift 
Bridge <--RelatedTo--> Walk <--RelatedTo--> Motion <--IsA-- Pursuit --DerivedFrom--> Pursue 