答案是：等价
证明如下：
1.a = 0,b = 0时,a || b == 0,!(a || b) == 1,!a && !b == 1
2.a = 0,b = 1时,a || b == 1,!(a || b) == 0,!a && !b == 0
3.a = 1,b = 0时,和2相同
4.a = 1,b = 1时,a || b == 1,!(a || b) == 0,!a && !b == 0
用代码证明如下：
#include
int main()
{
int a,b;
a = 0,b = 0;
if ((!(a || b)) == (!a && !b)) printf("Equal.\n");
a = 1,b = 0;
if ((!(a || b)) == (!a && !b)) printf("Equal.\n");
a = 0,b = 1;
if ((!(a || b)) == (!a && !b)) printf("Equal.\n");
a = 1,b = 1;
if ((!(a || b)) == (!a && !b)) printf("Equal.\n");
return 0;
}
输出结果如下：
Equal.
Equal.
Equal.
Equal.
