A trading system includes: a first set of two or more functions and a second set of two or more functions, wherein each of the functions in the first set and the second set includes a variable that is of a common variable type, wherein the value of the variable that is of the common variable type in the first set of functions and the value of the variable that is of the common variable type in the second set of functions may be different at a given point in time; and a function editing mechanism through which the value of the variable that is of the common variable type in the first set of functions may be edited for each of the functions in the first set of functions without affecting the value of the variable that is of the common variable type in the second set of functions.