Anchor: Its flow is constant never suffocated by the all-pervading sand or evaporated by the oppressive heat of the sun.
Entailed: The flow is unimpeded by its environment.
Contradiction: The flow is constantly disrupted by the sand and the sun.
Contradiction: A man riding a motorcycle.
Contradiction: What is this number known as productivity?
Contradiction: People planting a garden.
Contradiction: He stopped debating about what had happened in town.