NSEU, not as simple as just that, unfortunately.
Both could be misreading due a number of technical errors.
Of course, there could be multiple failures. I was just explaining the basics and
trying not to overcomplicate things. It's unlikely that both ADIRUs would fail and unlikely that both Captain's and F/O's probes would fail. Probe heat is supplied with power from independent sources (and will even tell you if it has failed).
What does the QRH say?