Reports possible EL problems, such as unresolved references and invalid EL locations.

Example:

Consider having function `exampleFun(String)` defined in the current namespace.


<jsp:root xmlns:example="urn:jsptld:exampleNamespace.tld">
  ${ example:exampleFun("1") + example:unknownFun("2") } // Error: cannot resolve function 'unknownFun'
  ${ example:exampleFun("1", "2") } // Error: different number of formal and actual parameters
</jsp:root>