And yet again, you simply write conclusions that don't follow from your premises. Which premises are logically combined to produce those conclusions, and by what rules of logic? What you wrote makes as much sense as:
Premise 1: Albany is the capital of New York.
Premise 2: Some bananas are yellow.
Conclusion: You owe me a million dollars.
Just setting down conclusions as if they're shown by premises without any assertion of logical rules or use of logical steps isn't a syllogism, it's continuing to beg the question.
Try this:
Premise 1: At t0<t1, God knows P at t1. (God knows Truman will choose to run for President before Truman makes that decision. No dispute.)
Premise 2: For all x, if God knows x, then x. (God's knowledge is infallible. No dispute.)
Premise 3: For all x at t, if God knows x before t, then ~C(~x). (If God knows something to be true before it happens, then it does not have the capacity to not happen. THIS PREMISE IS UNTRUE, and without it, I don't know of any way to get the contradiction you want. I would love to see you do so.)
Premise 4: C(~P) (At t1, Truman has the capacity to choose not to run for president. No dispute).
Substitution on 1,3: For P at t1, because God knows P before t1, Statement 5: ~C(~P).
Conjunction on 4,5: C(~P) and ~C(~P). Contradiction.
I invite troubleshooting if I've made an "elementary logical error" in the above.
So, again, if you just assume that God's knowledge of P before t1 implies ~C(~P), then you can arrive at a contradiction. That's the whole thing we're arguing, and I don't accept that assumption. Instead, I have repeatedly asserted that God's foreknowledge does not remove the capacity for counterfactual choices from agents. God knows those choices won't be made, but that doesn't imply that those choices cannot be made. The capacity persists.
If you can actually show a logical proof that doesn't include Premise 3 or a form thereof, I would love to see it.