Performs a logical AND operation.
Returns `1` if both values are nonzero, otherwise returns `0`.
land(value1, value2)
land(1, 1); // returns 1
land(1, 0); // returns 0
land(0, 5); // returns 0
land(3, -2); // returns 1
lnot land lor lxor lnand lnor lxnor