Commerce and substantial interstate activities are involved in these examples.

The city has substantial activity in urban design, historic preservation, and architecture.

The child cannot engage in any substantial gainful activity because of a physical or mental condition and 2).

Until the end of the war, he made substantial and vigorous activities to this end.

"We anticipate substantial activity in the Valdez area at first light," he messaged.

Inability to engage in substantial gainful activity means that if a person works, they earn less than a certain amount of money.

However, it has not been shown to have substantial activity in the tumors tested to this date.

There was no one in sight; the substantial activity of the afternoon seemed to have abated.

To meet the test, a person must be "unable to engage in any substantial gainful activity."

Living on light is a fine thing indeed, but it is not enough to sustain substantial activity.