例(3)

左辺	$\displaystyle =$	$\displaystyle A\cdot B\cdot(C+\overline{C})+B\cdot\overline{C}+A\cdot C ,\qquad\hspace{6ex} [$ 定理4(ii) $\displaystyle ] C+\overline{C}=1\$ と定理3(i)
	$\displaystyle =$	$\displaystyle (A\cdot B\cdot C+A\cdot C)+(A\cdot B\cdot \overline{C}+B\cdot\overline{C}), \quad[$ 定理4, 5 $\displaystyle ]$
	$\displaystyle =$	$\displaystyle A\cdot C+B\cdot\overline{C}, \hspace{29ex}[$ 定理9 $\displaystyle ]$
	$\displaystyle =$	右辺