Barcan formula
In quantified modal logic, the Barcan formula is the formula
\forall x.\, \Box P(x) \to \Box\, \forall x. P(x)
It is named after Ruth Barcan Marcus (1921-2012).
In quantified modal logic, the Barcan formula is the formula
\forall x.\, \Box P(x) \to \Box\, \forall x. P(x)
It is named after Ruth Barcan Marcus (1921-2012).