Foehn wind there is no precipitation, implies there must be other mechanisms. 2) Isentropic draw-down (the draw-down of warmer, drier air from aloft): When the approaching winds are insufficiently strong to propel the low-level air up and over the mountain barrier, the airflow is said to be 'blocked' by the mountain and only air higher up near mountain-top level is able to pass over and down the lee slopes as foehn winds. These higher source regions provide foehn air that becomes warmer and drier on the leeside after it is compressed with descent due to the increase in pressure towards the surface.
Single crossing condition ordered set. Such situations appear often in information economics, contract theory, social choice and political economics, among other fields. The term Single-Crossing Condition (Spence Mirrlees property) refers to the requirement that the isoutility curve for agents of different types cross only once. This condition guarantees that the transfer in a incentive-compatible direct mechanism can be pinned down by the transfer of the lowest type. This condition is similar to another condition called Strict Increasing Difference (SID). Formally, suppose the agent has a utility function formula_7, the SID says formula_8 we have formula_9. The Spence-Mirrlees Property is characterized by formula_10. Single