\item \lect Let $a$ and $b$ be Boolean variables.
Complete the python code with the appropriate variable declarations and constraint statements to check whether the following equivalence holds:
$$\lnot (a \land b) = (\lnot a \lor \lnot b).$$

  \vskip1em

  \begin{pythonSourceCode}
    from z3 import *

    solver = Solver()
    a, b = Bools("a b")
    l, r = Bools("l r")

    solver.add(l == Not(And(a, b)))
    solver.add(r == Or(Not(a), Not(b)))
    solver.add(Distinct(l, r))

    result = solver.check()
    print(result)
  \end{pythonSourceCode}
