Theorem: Assignment.add_of_both_eq_both (LeanSAT/LRAT/Assignment.lean)

State before:
b : Bool
⊢ addAssignment b both = both
Tactic:
rw [addAssignment]
State after:
b : Bool
⊢ (if b = true then addPosAssignment else addNegAssignment) both = both

State before:
b : Bool
⊢ (if b = true then addPosAssignment else addNegAssignment) both = both
Tactic:
split <;> decide
State after:
no goals