A constraint on the Invariance Principle. Serves to ensure that a metaphoric entailment that is incompatible with the target domain will fail to map. That is, the target domain can override a metaphoric entailment projected from the source domain in a way that preserves the cognitive topology ( conceptual structure ) of the target domain. To illustrate, consider the examples below which relate to the metaphor causation is transfer (of an object):

1. She gave him a headache state
2. She gave him a kiss event While the source domain for both of these examples is transfer, the first example relates to a state and the second to an event. The source domain transfer entails that the recipient is in possession of the transferred entity. However, while this entailment is in keeping with states, because they are temporally unbounded, the same entailment is incompatible with events, because they are temporally bounded and cannot therefore ‘stretch’ across time. This is illustrated below:
3. She gave him a headache and he still has it state
4. *She gave him a kiss and he still has it event Thus, in the case of the example in (4), the domain relating to events overrides the projection of the entailment of continued possession from the source domain as such an entailment is incompatible with this particular target.