(MODAL LOGIC)
Suppose we wanted a unary operator D with the followingsatisfaction condition. For any BML (Basic Modal Language) formulaϕ, BML model M, and world w ∈ W M M, w |= Dϕ iff there’s a v ∈ W Msuch that w 6= v and M, v |= ϕ Prove that this D operator is notBML definable.
Expert Answer
An answer will be send to you shortly. . . . .