A verification process evaluates the coefficient at a point inside the simulation domain. Should this evaluation point be, for example, at a singularity of the coefficient, then the coefficient is rejected.

Set up a coefficient that has a singularity at :

For a one-dimensional mesh with bounds from 0 to 1, the verification coordinate happens to be at . The coefficient is singular at the verification coordinate for this region:

Change the verification data such that the test coordinate is not at the singularity of :

More information can be found in the options section of InitializePDECoefficients.