void Frozen(void)


void Frozen(void) {
        int D = 100;

        while(D-->0) {
                troll_prog();
                fail_to_read_sicp();
        }
}

>>40
"valid assembly instruction" means code will execute on PC.
Explanation:
    All assembly instructions can execute on a PC.
    HCF opcode cannot execute on a PC.
    Therefore, HCF is not an assembly instruction.

See http://en.wikipedia.org/wiki/Validity
When an argument is set forth to prove that its conclusion is true (as opposed to probably true), then the argument is intended to be deductive. An argument set forth to show that its conclusion is probably true may be relatively valid if, whenever all premises are true, the conclusion is also necessarily true.

An argument that is not valid is said to be ‘’invalid’’.

An example of a valid argument is given by the following well-known syllogism:

    All men are mortal.
    Socrates is a man.
    Therefore, Socrates is mortal.

What makes this a valid argument is not the mere fact that it has true premises and a true conclusion, but the fact of the logical necessity of the conclusion, given the two premises. No matter how the universe might be constructed, it could never be the case that this argument should turn out to have simultaneously true premises but a false conclusion. The above argument may be contrasted with the following invalid one:

    All men are mortal.
    Socrates is mortal.
    Therefore, Socrates is a man.