On unsolvable $Q$-theories of ring varieties
    
    
  
  
  
      
      
      
        
Sibirskij žurnal čistoj i prikladnoj matematiki, Tome 18 (2018) no. 3, pp. 20-26
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			Let $\mathcal{M}$ be any proper variety of associative rings. We prove that there exists an infinite set of varieties of associative rings containing $\mathcal{M}$ with unsolvable $Q$-theories. In particular, this result is a positive solution to the Mal'cev problem from the Kourovka Notebook on the existence of such varieties.
			
            
            
            
          
        
      
                  
                    
                    
                    
                    
                    
                      
Keywords: 
quasivariety, variety, $Q$-theory, solvability, universal algebra, ring, Lee ring.
                    
                  
                
                
                @article{VNGU_2018_18_3_a1,
     author = {A. I. Budkin},
     title = {On unsolvable $Q$-theories of ring varieties},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {20--26},
     publisher = {mathdoc},
     volume = {18},
     number = {3},
     year = {2018},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2018_18_3_a1/}
}
                      
                      
                    A. I. Budkin. On unsolvable $Q$-theories of ring varieties. Sibirskij žurnal čistoj i prikladnoj matematiki, Tome 18 (2018) no. 3, pp. 20-26. http://geodesic.mathdoc.fr/item/VNGU_2018_18_3_a1/