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Separating the eraser Turing machine classes $$L_ e$$, $$NL_ e$$, $$co- NL_ e$$ and $$P_ e$$. (English) Zbl 0749.68036
The main result of the paper consists in the following: there are strong differences in the computational power of deterministic, nondeterministic, co-nondeterministic and alternating eraser Turing machines. The technique of the proof is based on exponential lower and polynomial upper bounds for read-once-only $$\Omega$$- branching programs.

##### MSC:
 68Q15 Complexity classes (hierarchies, relations among complexity classes, etc.) 68Q05 Models of computation (Turing machines, etc.) (MSC2010)
##### Keywords:
Turing machines; branching programs
Full Text:
##### References:
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