I think you misunderstood. I said there exists no algorithm such that for all formulas it can decide whether the formula represents an integer. Which is equivalent to saying that forall algorithms there exists a formula which can’t be decided.
In other words, the way this game is played, first you specify the algorithm and then I supply the formula that breaks it.
I understood that the algorithm valid for all formulae had to be produced in advance, but still I found it strange that it doesn’t exist. Further thinking about it it doesn’t seem so strange after all.
I think you misunderstood. I said there exists no algorithm such that for all formulas it can decide whether the formula represents an integer. Which is equivalent to saying that forall algorithms there exists a formula which can’t be decided.
In other words, the way this game is played, first you specify the algorithm and then I supply the formula that breaks it.
I understood that the algorithm valid for all formulae had to be produced in advance, but still I found it strange that it doesn’t exist. Further thinking about it it doesn’t seem so strange after all.