German mathematician Wilhelm Blaschke once called it a "hopeless" problem.

Decades later, New Jersey Institute of Technology professor Vladislav Goldberg shares the credit for solving it, according to a media report.

Blaschke, a pioneer in the branch of mathematics known as web geometry, had said in 1955 that it was nearly impossible to find the conditions under which a web might be transformed into a different kind of web with different numbers of nonintersecting, straight lines.

To describe such a transition mathematically would require leaps of logic and multitudes of calculations that were too great, Blaschke said.

Even as economic forecasters and theoretical physicists found uses for web geometry in subsequent decades, Blaschke's riddle remained.

There was, of course, one thing that was not available to Blaschke in the 1950s: a powerful computer.

Using advanced computer software, Goldberg — along with colleagues Maks Akivis of Ben-Gurion University in Israel, and Valentin Lychagin of Norway — solved the problem, The Star-Ledger reported.

The Journal of Geometric Analysis in March published Goldberg and Lychagin's paper, "On the Blaschke conjecture for 3-webs."

During the 1930s and '40s, Blaschke was a Nazi party member; Goldberg is a Russian-born Jew who had to struggle against anti-Semitism for decades during his career as a Soviet academic.

Goldberg, 70, however, is not smug over the accomplishment.

"I could never feel that way. Blaschke was a great mathematician," Goldberg, who retires next month, told the newspaper.