R. G. Jeroslow; "Redundancies in the Hilbert–Bernays Derivability Conditions for Gödel's Second Incompleteness Theorem"
著者
$ T \nvdash \forall_x.\lbrack \mathrm{Fml}(x) \land \mathrm{Pr}_T(x) \to \lnot\mathrm{Pr}_T(\dot{\lnot} x) \rbrack
remark:
$ \dot\lnot x = \ulcorner \lnot E_x \urcorner.