39XX 


Difference and functional equations 


3900 
General reference works (handbooks, dictionaries, bibliographies, etc.) 


3901 
Instructional exposition (textbooks, tutorial papers, etc.) 


3902 
Research exposition (monographs, survey articles) 


3903 
Historical (must also be assigned at least one classification number from Section 01) 


3904 
Explicit machine computation and programs (not the theory of computation or programming) 


3906 
Proceedings, conferences, collections, etc. 

39Axx 

Difference equations {For dynamical systems, see 37XX; for dynamic equations on time scales, see 34N05} 

39Bxx 

Functional equations and inequalities [See also 30D05] 