Answer the following question: Information: - Canada (French: ) is a country in the northern half of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering , making it the world's second-largest country by total area and the fourth-largest country by land area. Canada's border with the United States is the world's longest land border. The majority of the country has a cold or severely cold winter climate, but southerly areas are warm in summer. Canada is sparsely populated, the majority of its land territory being dominated by forest and tundra and the Rocky Mountains. About four-fifths of the country's population of 36 million people is urbanized and live near the southern border. Its capital is Ottawa, its largest city is Toronto; other major urban areas include Montreal, Vancouver, Calgary, Edmonton, Quebec City, Winnipeg and Hamilton. - The Canadian Labour Congress, or CLC (or ) is a national trade union centre, the central labour body in English Canada to which most Canadian labour unions are affiliated. - The Air Line Pilots Association , International ( ALPA ) is the largest pilot union in the world , representing more than 52,000 pilots from 31 U.S. and Canadian airlines . ALPA was founded in 1931 and is a member of the AFL - CIO and the Canadian Labour Congress . Known internationally as U.S. - ALPA , ALPA is also a member of the IFALPA . What is the relationship between 'air line pilots association' and 'trade union'?
Answer:
instance of