different symmetries play a role in understanding the meaning of a sentence. syntacticians have been aware of this issue and have used a variety of symmetries in their analyses. when the arabic syntax became familiar with the aristotelian logic and received some philosophical issues, most of the syntacticians focused upon the arabic symmetry and few attentions were directed towards other symmet...

A bstract By applying the stress-tensor-scalar operator product expansion (OPE) twice, we search for algebraic structures in d = 4 conformal field theories (CFTs) with a pure Einstein gravity dual. We find that rescaled mode defined by an integral of stress tensor T ++ on 2 plane satisfies Virasoro-like algebra when dimension scalar is large. The structure enhanced to include Kac-Moody-type if ...

Nonlinear symmetries of nite dimensional dynamical systems are related to nonlinear normal forms and center manifolds in the neighbourhood of a singular point. Certain abstract results can be used algorith-mically to construct the normal forms and/or the center manifold up to a given order in the perturbation expansion. We also argue that for this task, approximate symmetries are as useful as e...