David Boies of Boies, Schiller & Flexner and Keker & Van Nest’s Robert Van Nest could not have had more different days in court Tuesday.

In the copyright trial over smartphone technology, Google Inc. lead counsel Van Nest covered a lot of ground with a likable executive chairman Eric Schmidt, while Oracle Corp. lead counsel Boies battled a witness who would barely agree with him on what “cc” on an email means.

Boies began the day grilling Google’s top Android man, Andy Rubin, as Oracle aimed to show Google officials at the highest levels knew the Java technology it used in the Android operating system was subject to licensing with Sun Microsystems Inc., now an Oracle entity.

Picking up where he left off Monday, Boies introduced dozens of emails to or from Rubin that discussed whether Google needed to license certain technology and its need to avoid “fragmentation” of the computer program.

While the email chains look damning–and Oracle attorneys have made good use of them–Rubin didn’t give up anything easily.

“Are you familiar with the term fragmentation?” Boies asked, referring to a term widely used in computer programming circles in talking about compatibility issues. “Can you help me define it, please?” Rubin asked.

After that went on for a while, Rubin quibbled over whether he could tell who received a particular email–which plainly included three recipients–that Boies was trying to use against Google.

“There isn’t anybody else listed here, is there?” Boies said, sounding irritated.

Rubin responded meekly, “I want to be precise in answering your questions.”

“I don’t want to spend too much time on this, but this ought to be simpler than it is,” Boies said.

“When you see a ‘cc,’ you know that means they sent them a copy?” Boies asked.

“Right,” Rubin reluctantly offered.

The exchange took up several minutes, precious because San Francisco federal district court judge William Alsup has the parties on a clock, with just 17 hours allotted for each to put on its case.

Later in the morning, Schmidt, who served as Google CEO for a decade before moving to the executive chairman role last year, took the stand.

He told the jury that Sun was fine with Android’s use of Java, saying he knew that because he was in touch with former colleagues at Sun before Oracle acquired the company in 2010.

And he explained away emails and internal documents mentioning a need for licensing as either expressing an incorrect position or referring to a different piece of proprietary information altogether.

“My understanding is that what we were doing was permissible,” Schmidt said. It was “legally correct,” he added.

And in discussing the finer points of APIs, or application programming interfaces, 37 of which are at the heart of the dispute, Schmidt gave a lengthy lesson in computer science.

Oracle contends the Java APIs are copyrightable, and that Google needed a license to use that technology.

Van Nest asked Schmidt, a software engineer, if that part of the Java technology is like a blueprint, as Oracle attorneys have asserted.

“No, they are not,” he said.

Van Nest asked how long he’d held that belief.

“Since I’ve been a computer scientist,” Schmidt said, “so, 40 years.”

Oracle will present its patent infringement claims in the next phase of trial, which is supposed to last another seven weeks.

This article originally appeared in The Recorder.