getOriginal
Retrieves the original variable name of the provided variable, if any, or null otherwise
Consider for instance the substitution { X -> Y, Y -> Z }, then the invocation of getOriginal(Z) should retrieve X
Retrieves the original variable name of the provided variable, if any, or null otherwise
Consider for instance the substitution { X -> Y, Y -> Z }, then the invocation of getOriginal(Z) should retrieve X