split
assignment : Assignment
b : Bool
⊢ (if b = true then hasPosAssignment else hasNegAssignment)
      ((if b = true then addPosAssignment else addNegAssignment) assignment) =
    true
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