Instead of following handwritten instructions, machine-learning algorithms devise their own solution to thorny problems.

And once they reached the village, they would have other thorny problems to resolve.

Coworkers often went to him with particularly thorny problems.

Here are five thorny problems that experts will be bending their brains against next year.

Likewise, all professions have their thorny problems that have been debated in their ranks for generations.

But India's backyard is a thicket of thorny problems, even if huge opportunities for commerce and other exchanges do exist.