NON-RECURSIVE TRADE-OFFS FOR TWO-WAY MACHINES
Christos A. Kapoutsis · International Journal of Foundations of Computer Science · 2005
If the machines of some type A have enough resources to (i) solve problems that no machine of type B can solve, and (ii) simulate any unary two-way deterministic finite automaton that has access to a linearly-bounded counter, then typically no recursive function can upper bound the increase in the size of description when a machine of type A is replaced by an equivalent machine of type B.