Anchor: Using cost models to estimate the cost and length of time necessary to develop a new software system, for example, is appropriate only after requirements have been defined, a system design has been developed, and the size of the new system has been estimated.
Entailed: You can only use cost models in certain circumstances.
Contradiction: You can always use cost models
Contradiction: An empty bucket.
Contradiction: People are walking.
Contradiction: Two women are feeding pigieons.
Contradiction: A person is wearing a backpack.