(NBC News) As same-sex couples wait for the Supreme Court to decide if it will hear one of five challenges to a law that bans federal recognition of gay marriage, opening arguments were heard Thursday in one such case in New York.

The case before the U.S. 2nd Court of Appeals concerns Edith Windsor and Thea Spyer, a lesbian couple who lived together in New York City for 44 years and formally married in Canada in May 2007. While this case is still in earlier stages of the court process, attorneys have also asked the nation’s top court to bundle the case with the others in the legal battle against the Defense of Marriage Act across the nation.

The state of New York recognized the marriage of Windsor and Spyers, but federal law did not because of the Defense of Marriage Act, which restricts the definition of marriage to a union between a man and a woman.

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