How PEMAG is calculated in ABAQUS?

[Lansir]

I'm wondering how PEMAG is calculated in ABAQUS.
In theory, the equivalent plastic strain can be calculated based on the deviator tensor of plastic strain.
In the documentation, the calculation is based on the double-dot product of ε^pl tensor.
So, what is this ε^pl tensor? Just the PE components?

Thank you very much!

 

[Mustaine3]

I don't know the details, but I guess they split the strain tensor in an elastic and plastic part. And probably also into other components like creep and thermal if necessary.