##### Check function is functionally complete or not

f(A,B,C)=A'+BC'   check functionally complete or not

If we are able to derive  (AND,NOT) or  (OR,NOT) then it is functionally complete otherwise not

For completement(Not) :

Do like this it is easy to find compliment

put f(A,A,A) orF(B,B,B) or f(C,C,C)

then we get completement, let we put f(A,A,A )in given function then we get

f(A,A,A)=A'.......(We got Completementi.e NOT)

Now try for 'OR' or 'AND'

Let check for 'OR' i.e f(A,B,C)=A+B

so put f( f(A,A,A),B,F(B,B,B))  in given function  SO,

f( f(A,A,A),B,F(B,B,B) )=A+B.....( since we know  f(A,A,A)=A'  F(B,B,B)=B')

therefore we are able to get  'NOT' and 'OR'  so  this function is functionally complete

Note :If the given expression is not having any complement variable then it is not possible to get any complement(i.e NOT).Then directly we can say to that function is not functionally complete.

Example : f(A,B,C)=AB+BC+CA in this example we have no complemented variable then by looking directly to function we can say it is not  functionally complete.

##### 1Comment
Anjali
9 Aug 2019 02:36 pm
Ok