a contract whose performance depends on a fact or event that affects legal relations
权威例句
1.
As Michael Kinsley recently explained, however, that term properly refers to contracts that make employment conditional on union membership.
FORBES: Why Milton Friedman Opposed Right-To-Work
2.
In the fortieth-anniversary edition of Capitalism and Freedom (2002) he stated that he was equally opposed to right-to-work laws and to yellow-dog contracts, which make employment conditional on not belonging to a union.