// convert function of a single Pair argument to a function of two arguments
            // parameter f is a function of a Pair
            // returns a function of two arguments
            function toBiFunction(f)
            {
                function temp(a, b)
                {
                    p = new Pair(a, b); // turn 2 values into a Pair
                    return f(p); // return teh function of that Pair
                }
                return temp;
            }

            function f1(pair) // example function of a Pair
            {
                // check type of argument
                if (pair.kind!=="Pair") throw "Not a pair";
                // exampel function body
                return pair.getFirst() + pair.getSecond();
            }


            function Pair(a, b) { // in effect, define a Pair class (actually function constructor)
                this.kind="Pair";
                this.firstField = a;
                this.secondField = b;
                this.getFirst = getFirst1;
                this.getSecond = getSecond1;

                function getFirst1()
                {
                    return this.firstField;
                }
                function getSecond1()
                {
                    return this.secondField;
                }


            }


            p1 = new Pair(1, 2); // make a Pair
            console.log(p1.getFirst()); // 1
            funcPair=f1; // make an example function object of a Pair
            // console.log(funcPair(7)); this throws an exception - cannot apply funcPair to singleton
            console.log(funcPair(p1)); // 3 - check funcPair working
            funcBi = toBiFunction(funcPair); // create a biFunction
            console.log(funcBi(7,8)); // 15