A ruling in the Kroger-Albertsons merger case will hinge on how Judge for Oregon Adrienne Nelson interprets a 1980s-era definition of the grocery industry.

On Monday, the CEOs for Kroger and Albertsons were pushed, and pushed back, over whether the two grocery retailers need to merge.

An attorney directed particular ire toward the New Hampshire-based company, C&S Wholesale Grocers, which would acquire 579 stores sold off by the grocer after they combined.