Ruby, Software Development, Boolean, Augustus De Morgan.
party" p && q # The person is 18 and admitted into the party !(p && q) # the person is either not 18, or not allowed in the party. # now we can flip this using de morgans 1st law (!p || !q) # the person is either not 18, or not allowed in the party. #so... you can see that these are logically the