General: Fundamental condition
enforced by courts, even if it is not expressly included in a contract document
by the contracting parties. In law, an unwritten requirement (that is deemed
important in light of the facts and circumstances of a contract) implies a condition (called condition precedent) of the contract. For example, if a quantity
of umbrellas is ordered to be delivered before the rainy season but they arrive only after the season has ended, that order
may be cancelable even if the words "Time is of the essence" are not included in the order.