  Although logic of quantum mechanics has been studied for a long time, logic
of QFT has not been studied before. We formulate logic of QFT by introducing
the perspective of dynamic logic, because the nature of two fundamental
operators in QFT, namely creation and annihilation operators, is dynamic in the
sense of logic. After we formulate dynamic logic of QFT, we give a dynamic
logical interpretation of fermions, the so-called vacuum state, the zero vector
and propagators in QFT. We also emphasize that only a tautology $\top$ and a
contradiction $\bot$ are atomic formulas of our logic. Finally, we show how
Aharonov-Bohm effect can be explained naturally from our dynamic logic of QFT.
This paper should be the beginning of studying logic of QFT from a dynamical
point of view.
