The logic of unboundedly reactive systems

Scientific theories often need to envision that a given output variable Y is jointly determined by all input variables of a certain kind ΣX that we can identify onlyas a kind without knowing all its specific instances or even how many of these there are, When the number of variables in ΣX is possibly infinite, the function by which they determine Y proves to be enormously enigmatic, epistemically, mathematically, and scientifically