have := existsWitnessPath_rtl M wit.length v δ ξ wit
case mpr.intro
W : Type
ξ : Formula
M : KripkeModel W
δ : List Program
v : W
wit : witness M v δ ξ
⊢ ¬evaluate M v (⌈⌈δ⌉⌉ξ)
case mpr.intro
W : Type
ξ : Formula
M : KripkeModel W
δ : List Program
v : W
wit : witness M v δ ξ
this : wit.length = wit.length → evaluate M v (~⌈⌈δ⌉⌉ξ)
⊢ ¬evaluate M v (⌈⌈δ⌉⌉ξ)