intro v hv
ν : Type u_1
inst✝ : DecidableEq ν
τ : PropAssignment ν
xs : Finset ν
τ' : PropAssignment ν
⊢ agreeOn (↑xs) (setMany τ xs τ') τ'
ν : Type u_1
inst✝ : DecidableEq ν
τ : PropAssignment ν
xs : Finset ν
τ' : PropAssignment ν
v : ν
hv : v ∈ ↑xs
⊢ setMany τ xs τ' v = τ' v