Alternative form of when one door closes, another opens

Alternative form of when one door closes, another opens

When one opportunity is lost, another opportunity soon becomes available.

plural of closed file

(chess) A file with pawns of both colors on it.

(engineering, thermodynamics) A feedwater heater in which the two fluid streams do not mix.

plural of closed feedwater heater

plural of closing time

(category theory) A cartesian closed category which also has an initial object and such that for any pair of objects, A and B, in the category, the category has another object which is their coproduct, A∐B.

(category theory) A category which has a terminal object and which for every two objects A and B has a product A × B and an exponential object Bᴬ.