byCases H: head.fst = v'
case cons
α σ : Type
ε : σ → Type
α✝ σ✝ : Type
ε✝ : σ✝ → Type
δ : Dialect α✝ σ✝ ε✝
v v' : SSAVal
Hne : v' ≠ v
τ : MLIRType δ
val : MLIRType.eval τ
head : SSAVal × (τ : MLIRType δ) × MLIRType.eval τ
tail : List (SSAVal × (τ : MLIRType δ) × MLIRType.eval τ)
tail_ih✝ : getT v (set v' τ val tail) = getT v tail
⊢ getT v (if head.fst = v' then (head.fst, { fst := τ, snd := val }) :: tail else head :: set v' τ val tail) =
    if head.fst = v then some head.2 else getT v tail
case cons.h1
α σ : Type
ε : σ → Type
α✝ σ✝ : Type
ε✝ : σ✝ → Type
δ : Dialect α✝ σ✝ ε✝
v : SSAVal
τ : MLIRType δ
val : MLIRType.eval τ
head : SSAVal × (τ : MLIRType δ) × MLIRType.eval τ
tail : List (SSAVal × (τ : MLIRType δ) × MLIRType.eval τ)
Hne : head.fst ≠ v
tail_ih✝ : getT v (set head.fst τ val tail) = getT v tail
⊢ (if head.fst = v then some { fst := τ, snd := val } else getT v tail) =
    if head.fst = v then some head.2 else getT v tail

case cons.h2
α σ : Type
ε : σ → Type
α✝ σ✝ : Type
ε✝ : σ✝ → Type
δ : Dialect α✝ σ✝ ε✝
v v' : SSAVal
Hne : v' ≠ v
τ : MLIRType δ
val : MLIRType.eval τ
head : SSAVal × (τ : MLIRType δ) × MLIRType.eval τ
tail : List (SSAVal × (τ : MLIRType δ) × MLIRType.eval τ)
tail_ih✝ : getT v (set v' τ val tail) = getT v tail
H : ¬head.fst = v'
⊢ (if head.fst = v then some head.2 else getT v (set v' τ val tail)) = if head.fst = v then some head.2 else getT v tail