Tell the compiler/computer to execute each new "IsChecked" invocation as double as fast as the current "IsChecked" invocation. Since 1 (the time of the first IsChecked) + 1/2 (the time of the second IsChecked) + 1/4 + ... + 1/2^n converges to 2 for n -> Inf, you have the result of "IsChecked" in 2 time units ;) But Achilles wishes from Zeus, who executes every wish, that his wish mustn't come true and the world crashes... (that was an insider from the same book)
If you find spelling- or grammer-mistakes, please let me know, so that I can correct them (at least for me) - english is not my first language...