##  [Sub and Supersolution Method](/sub-and-supersolution-method) 

  ##  [Sub and Supersolution Method](https://mathlogic.quantumdictionary.io/sub-and-supersolution-method-0) 

  

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**Mathematics & Logic Dictionary**

 







 

 

 

 



 

 

 

 

Definition

A comparison technique that constructs an ordered pair of functions—a subsolution below and a supersolution above the sought solution—then uses monotone iteration, topological or variational arguments to obtain existence and often bounds (and sometimes uniqueness) for solutions of nonlinear differential or variational problems.