cases p
case r240.r240
p : State
⊢ r240 + r240 +ᵥ p = r240 +ᵥ (r240 +ᵥ p)
case r240.r240.s0

⊢ r240 + r240 +ᵥ s0 = r240 +ᵥ (r240 +ᵥ s0)

case r240.r240.s120

⊢ r240 + r240 +ᵥ s120 = r240 +ᵥ (r240 +ᵥ s120)

case r240.r240.s240

⊢ r240 + r240 +ᵥ s240 = r240 +ᵥ (r240 +ᵥ s240)