tingimus, mille kohta on tehingu tegemise ajal teada, et see ei saabu
a condition precedent or subsequent in a contract which, at the time when the contract is entered into, purports to bind a party to do that which is absolutely impossible in itself. (Ballentine, 3rd ed. 1969, p. 592)
(Conditions) are possible or impossible; ... the latter when it is contrary to the course of nature or human limitations that they should ever be performed. (Black, 5th ed. 1979, p. 266).
