full_adder fa0(A[0],B[0],Cin,S[0],c1); full_adder fa1(A[1],B[1],c1,S[1],c2); full_adder fa2(A[2],B[2],c2,S[2],c3); full_adder fa3(A[3],B[3],c3,S[3],Cout); ...