In 1973 Altshuller proposed the first two methods of resolving physical contradictions by separating in time or in space . At the time he claimed that no other methods were possible or needed. Nevertheless, in 1974 the author introduced the concept of resolution of physical contradictions by separating contradictory requirements to the opposite "sides"/views/representations of an object  and subsequently discovered separation in structure (separation to parts and to the whole). Since then the development of the methods of contradictions resolution rotated around the search for new separation principles (see e.g. [3, 4, 5]).
However, the author never made public that some contradictions can be resolved not by separating contradictory requirements but by their uniting.
Consider, for example, the following problem. The flat bridge has that drawback that needs supports in the middle:
On the other hand, the arch bridge
Thus, we have a contradiction: the bridge has to be flat in order to not affect traffic (to not require slowdown) and has to be arch in order to not have supports in the middle. As is known, the contradiction can be resolved by UNITING the contradictory requirements rather than separating: the bridge is made of two bridges, the flat and the arch. The arch supports the flat bridge from below:
R E F E R E N C E S: