Definition: We call an agent wireheaded if it systematically exploits some discrepancy between its true utility calculated w.r.t reality and its substitute utility calculated w.r.t. its model of reality.
How do you tell the difference between reality and your model of reality?
How do you tell the difference between reality and your model of reality?
Because your model makes predictions about your future observations that may either be supported or refuted by those observations—why do you ask?