It's an impossible combination but that's how it is.

When all the impossible combinations have been eliminated, the remaining state combinations are valid, and thus can be combined.

For the essence of a riddle is to express true facts under impossible combinations.

When you add to all that the mountains that border their land - it is an impossible combination.

Into this environment comes DTrace, which proposes the following seemingly impossible combination of features.

Powerful and playful seemed like an impossible combination.

Believe me, it would take you a week just to rule out impossible combinations of the main variables.

Unlike the others, he said lowering taxes, increasing defense spending, and balancing the budget were an impossible combination.

Thanks to digital technology, those generations mix in logically impossible combinations.

He was very American except that he had no energy at all, an impossible combination, we thought.