0^0 is undefined. The reason:
1. 0^x=0 for all positive x. For continuity, 0^0 should be defined as 0.
2. But x^0=1 for all positive x. For continuity, 0^0 should be defined as 1.
So there is no definition for 0^0.
Note x^x goes to 1 as x goes to 0.
Any defition of 0^0 may violate exponential rules.