/**
 * The AddSubtract actor from the Ptolemy library.
 *
 * @author JWJ
 */

actor AddSubtract [T < Number]
    ()
    multi T AddInput, multi T SubtractInput ==> T Result :


    action AddInput: [a] any, SubtractInput: [s] any ==> [result] 
    guard dom a != {} or dom s != {}
    var T result := 0 
    do
        foreach Integer i in dom a do
            result := result + a[i];
        end
        foreach Integer i in dom s do
            result := result - s[i];
        end
    end
end