-  Example:
        do {
                putchar(' ');
                column++;
        } while (column & 07);
Rule:
a & b /* is sometimes used for */ a % (b + 1) /* b = 2**n - 1 */
 
-  Example:
    n = ((dp - cp) << 2) + 1; /* 4 times + NULL */
Rule:
a << n /* is sometimes used for */ a * k /* k = 2**n */
 
-  Example:
bp = bp1 + ((bp2 - bp1) >> 1);
Rule:
a >> n /* is sometimes used for */ a / k /* k = 2**n */