abcD+abcd+aBCd+aBCD
then the simplified function is
( Capital letters are copliments of corresponding letters
A=compliment of a)
[a] a [b] ab [c] abc [d] a(bc)* [e] mone
(bc)*=compliment of bc
since capital letters are the complements...
(abcD+abcd)+(aBCd+aBCD)..taking them separately...
solving for the 1st bracket...abc(D+d)=abc{D+d=0}
solving for the 2nd bracket...aBC(d+D)=aBC{D+d=0}
==abc+aBC=a(bc+BC)
=a*0
=0