设
a = p1e1p2e2⋯prera\ =\ p_1^{e_1}p_2^{e_2}\cdots p_r^{e_r}a = p1e1p2e2⋯prer b = p1f1p2f2⋯prfrb\ =\ p_1^{f_1}p_2^{f_2}\cdots p_r^{f_r}b = p1f1p2f2⋯prfr 则 gcd(a,b) = p1min(e1,f1)p2min(e2,f2)⋯prmin(er,fr)\gcd(a,b)\ =\ p_1^{\min(e_1,f_1)}p_2^{\min(e_2,f_2)}\cdots p_r^{\min(e_r,f_r)}gcd(a,b) = p1min(e1,f1)p2min(e2,f2)⋯prmin(er,fr) lcm(a,b) = p1max(e1,f1)p2max(e2,f2)⋯prmax(er,fr)\text{lcm}(a,b)\ =\ p_1^{\max(e_1,f_1)}p_2^{\max(e_2,f_2)}\cdots p_r^{\max(e_r,f_r)}lcm(a,b) = p1max(e1,f1)p2max(e2,f2)⋯prmax(er,fr)
这如何严谨证明