49-01 Instructional exposition (textbooks, tutorial papers, etc.)

49-02 Research exposition (monographs, survey articles)

49-03 Historical (must also be assigned at least one classification number from Section 01)

49-04 Explicit machine computation and programs (not the theory of computation or programming)

49-06 Proceedings, conferences, collections, etc.

49J05 Free problems in one independent variable

49J10 Free problems in two or more independent variables

49J15 Optimal control problems involving ordinary differential equations

49J20 Optimal control problems involving partial differential equations

49J21 Optimal control problems involving relations other than differential equations

49J27 Problems in abstract spaces [See also <a href="#code:90C48">90C48</a>, <a href="#code:93C25">93C25</a>]

49J30 Optimal solutions belonging to restricted classes (Lipschitz controls, bang-bang controls, etc.)

49J40 Variational methods including variational inequalities [See also <a href="#code:47J20">47J20</a>]

49J45 Methods involving semicontinuity and convergence; relaxation

49J50 Fréchet and Gateaux differentiability [See also <a href="#code:46G05">46G05</a>, <a href="#code:58C20">58C20</a>]

49J53 Set-valued and variational analysis [See also <a href="#code:28B20">28B20</a>, <a href="#code:47H04">47H04</a>, <a href="#code:54C60">54C60</a>, <a href="#code:58C06">58C06</a>]

49J55 Problems involving randomness [See also <a href="#code:93E20">93E20</a>]

49J99 None of the above, but in this section

49K05 Free problems in one independent variable

49K10 Free problems in two or more independent variables

49K15 Problems involving ordinary differential equations

49K20 Problems involving partial differential equations

49K21 Problems involving relations other than differential equations

49K27 Problems in abstract spaces [See also <a href="#code:90C48">90C48</a>, <a href="#code:93C25">93C25</a>]

49K30 Optimal solutions belonging to restricted classes

49K40 Sensitivity, stability, well-posedness [See also <a href="#code:90C31">90C31</a>]