Function isolate_b_compute 

pub fn isolate_b_compute(prompt: NQuin) -> Option<NQuin>

Run Isolate B’s real computation for a prompt quin and return the consequence quin.

The four semantic fields seed a 2×2 · 2×2 product (a real dense-linear kernel run through LocalKernelExecutor); the product is folded into the output’s object. The output is a genuine function of every input field — never a constant. On the (unreachable for a well-formed 2×2) kernel error, returns None rather than fabricating a result.