In Hale vs. Finch 1877 - "And it is understood and agreed, that this sale is upon this express condition, that said steamboat or vessel is not within 10 years from the first day of May, 1867, to be run upon any of the routes of travel on the rivers, bays, or waters of the state of California or the Columbia river or its tributaries"

Is that express condition precedent, or express condition concurrent, or neither?