39XX 


Difference and functional equations 

39Bxx 

Functional equations and inequalities [See also 30D05] 


39B05 
General 


39B12 
Iteration theory, iterative and composite equations [See also 26A18, 30D05, 37XX] 


39B22 
Equations for real functions [See also 26A51, 26B25] 


39B32 
Equations for complex functions [See also 30D05] 


39B42 
Matrix and operator equations [See also 47Jxx] 


39B52 
Equations for functions with more general domains and/or ranges 


39B55 
Orthogonal additivity and other conditional equations 


39B62 
Functional inequalities, including subadditivity, convexity, etc. [See also 26A51, 26B25, 26Dxx] 


39B72 
Systems of functional equations and inequalities 


39B82 
Stability, separation, extension, and related topics [See also 46A22] 


39B99 
None of the above, but in this section 