Classical unified field theories since antisymmetry seemed essential for electromagnetism, the symmetry requirement was relaxed for one or both fields. Einstein's proposed unified-field equations (fundamental laws of physics) were generally derived from a variational principle expressed in terms of the Riemann curvature tensor for the presumed space-time manifold. In field theories of this kind, particles appear as limited regions in space-time in which the field strength or the energy density are particularly high. Einstein and coworker Leopold Infeld managed to demonstrate that, in Einstein's final theory of the unified field, true singularities of the field did have trajectories resembling point particles. However, singularities are
Unified Command of the area east of the canal (Egypt) first changed the force structure of the army by creating a "unified command" to oversee counterterrorism operations east of the Suez Canal. The second promoted Osama Askar, commander of the Third Field Army, both in rank and in title: he is now a lieutenant general—one of a handful in the armed forces—and in charge of the "unified command." He will also retain his seat on the SCAF. Askar’s former deputy, Muhammad Abdullah, has been appointed commander, and Tarek Anwar Helal the chief of staff, of the Third Field Army. Nasr 13 was the first manoeuvre of its type since the