Hi, in my assignment, I have been trying and trying to get the disjunctive normal form of a boolean expression as follows:

(p AND (q AND NOT( r AND p))) OR NOT(p OR NOT(r))

I can getNOT(p OR NOT(r))down to its disjunctive normal form(NOT p AND r)However I cant get

(p AND (q AND NOT( r AND p)))down to its disjunctive normal form.

Could anyone please shed any light on my problem?

Many Thanks in Advance, Wilson.