Basic Cancer & I Substitute theorems If replacing all variable A in a logic equation with a logic function F, the equation would keep in equivalent F1(a1, a2.am)=F2(a1, a2.am) substitute f(x1.xn) for ai: F1(a1, a2..f,am) F2(a1a2…,f,am Ex。A(B+C)=AB+AC R substitute A+D for A (A+D)(B+C=(A+D)B+(A+D)CBasic Concept Substitute theorems If replacing all variable A in a logic equation with a logic function F ,the equation would keep in equivalent. F1(a1,a2……am)= F2(a1,a2……am) substitute f(x1…xn) for ai: F1(a1,a2…,f,…am)= F2(a1,a2…,f,…am) Ex . A(B+C)=AB+AC substitute A+D for A: (A+D)(B+C)=(A+D)B+(A+D)C