Added test cases for bus structure

data/Example3.circom

@@ -0,0 +1,74 @@
+bus B1(){
+    signal x;
+}
+
+bus B2() {
+    signal x;
+}
+
+template B1toB2(){
+    input B1() b1;
+    output B2() b2;
+    b2 <== b1;
+}
+
+bus Film() {
+    signal title[50];
+    signal director[50];
+    signal year;
+}
+
+bus Date() {
+    signal day;
+    signal month;
+    signal year;
+}
+
+bus Person() {
+    signal name[50];
+    Film() films[10];
+    Date() birthday;
+}
+
+bus Line(dim){
+    PointN(dim) start;
+    PointN(dim) end;
+}
+
+bus Figure(num_sides, dim){
+    Line(dim) side[num_sides];
+}
+
+bus Triangle2D(){
+    Figure(3,2) {well_defined} triangle;
+}
+
+bus Square3D(){
+    Figure(4,3) {well_defined} square;
+}
+
+template well_defined_figure(num_sides, dimension){
+    input Figure(num_sides,dimension) t;
+    output Figure(num_sides,dimension) {well_defined} correct_t;
+    var all_equals = 0;
+    var isequal = 0;
+    for(var i = 0; i < num_sides; i=i+1){
+        for(var j = 0; j < dimension; j=j+1){
+            isequal = IsEqual()([t.side[i].end.x[j],t.side[(i+1)%num_sides].start.x[j]]);
+            all_equals += isequal;
+        }
+    }
+    all_equals === num_sides;
+    correct_t <== t;
+}
+
+template Edwards2Montgomery () {
+ input Point() { edwards_point } in ;
+ output Point() { montgomery_point } out ;
+
+ out.x <-- (1 + in.y ) / (1 - in.y ) ;
+ out.y <-- out.x / in.x ;
+
+ out.x * (1 - in.y ) === (1 + in.y ) ;
+ out.y * in.x === out.x ;
+}