This object purpose is mainly for displaying inline figures for the teaching of calculation.
It's goal is to know if a function of one, two or three variables depend on one of it's variables.
The test is made without simplifying the calculation of the function.
The value returned is 1 if the formula depends on the chosen variable and else 0.
For example, a function defined by f(x,y) = x^2 +2*y - x^2 will be considered dependant of x and y.
But a function defined by f(x,y,z)=x^2+y will be considered as non dependent on z and dependent on x and y.
To define such an object, use icon of the calculations expandable bar (third from the bottom)..