>>26
Suppose that we have a method of always inferring the value of a variable in a static language. And suppose we would like to know if an algorithm, A will halt or not. We can construct a new algorithm, B
function B()
if(halts(A))
a = 1
else
a = 0
end
print(a)
end
We use the method to find out what the value of a will be when it is printed. If a is 1, then A halts. If a is 0, then A will not halt.