1. This world is discrete, regardless of matter, energy, or time (quantum theory, Zeno's paradox, etc.) 2. Discreteness leads to "inaccuracy". For example, suppose that our world The minimum factor is 0.01. If there is a certain "necessity formula set" A (this formula can be used to deduce the behavior and position at any time), and a value of 0.003 is calculated, then this value does not exist in real life, it may be used The nearest principle "rounding from 4 to 6" (or "rounding from 4 to 6" or other) becomes 0.00 3. If "rounding from 4 to 6" is used as formula set B, then A and B must also be a "necessity formula set" " 4. But there is another possibility, that is, it is at the middle point "5" and cannot be "rounded from 4 to 6"; in this case, randomness will inevitably occur. For example, if 1.005 is calculated based on A and B, it may become 1.00 , may also become 1.01. Therefore, "contingency" is introduced into the general environment of "inevitability". Conclusion: If our world is discrete (regardless of whether there is "most" "inevitability"), "contingency" It must exist (regardless of the fact that its scope of action may be small)