. rw [hasPosAssignment, addPosAssignment]
  cases assignment <;> simp
case isTrue
assignment : Assignment
b : Bool
h✝ : b = true
⊢ assignment.addPosAssignment.hasPosAssignment = true

case isFalse
assignment : Assignment
b : Bool
h✝ : ¬b = true
⊢ assignment.addNegAssignment.hasNegAssignment = true
case isFalse
assignment : Assignment
b : Bool
h✝ : ¬b = true
⊢ assignment.addNegAssignment.hasNegAssignment = true