Simplification of the expression using De-Morgan's rule Simplify the following expressions to the simplest expression using De Morgan’s
theorem and Boolean algebra.
¬(A(¬(B+¬C))D)=¬(AD(¬(B+¬C))
          =¬(AD)+¬(¬(B+¬C))
          =¬(AD)+(B+¬C)
          =¬(AD)+B+¬C 

is the solution correct?
Many thanks!

I am reading this as:
$\neg (A \land \neg (B \lor \neg C) \land D)$
which by DeMorgan would be:
$\neg A \lor (B \lor \neg C) \lor \neg D$
i.e.
$\neg A + B + \neg C + \neg D$
