CalculusLike

The main task of the initializer is to handle creation of reactives, especially during an ongoing propagation. The formalization does not support this, to keep the complexity of the proofs in check.

The formalization uses a per device store mapping reactives to their inputs, values, and operator. The operator is already handled by the common implementation, so we keep the value and inputs. The store mapping does not exist as a single object, but instead each reactive has this state.