It is often found convenient to designate one of the reactions of a statically indeterminate structure as redundant and to eliminate the corresponding support. Since the stated conditions of the problem cannot be arbitrarily changed, the redundant reaction must be maintained in the solution. But it will be treated as an unknown load which, together with the other loads, must produce deformations that are compatible with the original constraints. The actual solution of the problem is carried out by considering separately the deformations caused by the given loads and by the redundant reaction, and by adding — or superposing — the results obtained. The general conditions under which the combined effect of several loads can be obtained in this way are discussed in the lesson Multiaxial Loading and Generalized Hooke's Law.