Consider again the same function as in Q$1,$ but with a changed precondition:

def f$($x$)$:

$\text{'}\text{'}\text{'}$ Pre: x is a natural number greater than $997\text{'}\text{'}\text{'}$

a $=$ x

y $=10$

while a $>0$:

a $=$ a $-$ y

y $=$ y $-1$

return a $*$ y

Assuming the function terminates, what would be a correct variant that?

Question $2$Answer

a$.$

a$-$y is a variant

b$.$

y$-1$ is a variant

c$.$

a$+$y is a variant

d$.$

None of the above is a variant for this function.