diff --git a/js/graphics/SVGArrow.ts b/js/graphics/SVGArrow.ts
index 43ff977..2bda327 100644
--- a/js/graphics/SVGArrow.ts
+++ b/js/graphics/SVGArrow.ts
@@ -1,9 +1,9 @@
 import { HTMLappendIt, Positionable, svgNamespace } from "../types";
 
 export class SVGArrow implements HTMLappendIt {
-    group;
-    lineText;
-    line;
+    group: SVGElement;
+    lineText: SVGElement;
+    line: SVGElement;
     from: Positionable;
     to: Positionable;
     constructor(from: Positionable, to: Positionable) {
@@ -34,10 +34,10 @@ export class SVGArrow implements HTMLappendIt {
         let l = Math.sqrt(dx * dx + dy * dy);
         dx /= l;
         dy /= l;
-        this.line.setAttribute('x1', this.from.x + dx * 30);
-        this.line.setAttribute('y1', this.from.y + dy * 30);
-        this.line.setAttribute('x2', this.to.x - dx * 40);
-        this.line.setAttribute('y2', this.to.y - dy * 40);
+        this.line.setAttribute('x1', (this.from.x + dx * 30) + "");
+        this.line.setAttribute('y1', (this.from.y + dy * 30) + "");
+        this.line.setAttribute('x2', (this.to.x - dx * 40) + "");
+        this.line.setAttribute('y2', (this.to.y - dy * 40) + "");
     }
     appendIt(svg) {
         svg.appendChild(this.group);
diff --git a/js/graphics/SVGNode.ts b/js/graphics/SVGNode.ts
index a8db426..68d8447 100644
--- a/js/graphics/SVGNode.ts
+++ b/js/graphics/SVGNode.ts
@@ -2,10 +2,10 @@ import { HTMLappendIt, svgNamespace } from "../types";
 import { Tragable } from "./tragable";
 
 export class SVGNode extends Tragable implements HTMLappendIt {
-    group;
-    circle;
-    circleText;
-    aboveText;
+    group: SVGElement;
+    circle: SVGElement;
+    circleText: SVGElement;
+    aboveText: SVGElement;
     constructor(node) {
         super();
         // Create the group element
diff --git a/js/graphics/SVGTransition.ts b/js/graphics/SVGTransition.ts
index c3fcf2f..c0b8df2 100644
--- a/js/graphics/SVGTransition.ts
+++ b/js/graphics/SVGTransition.ts
@@ -2,9 +2,9 @@ import { HTMLappendIt, svgNamespace } from "../types";
 import { Tragable } from "./tragable";
 
 export class SVGTRansition extends Tragable implements HTMLappendIt {
-    group;
-    rect;
-    rectText;
+    group: SVGElement;
+    rect: SVGElement;
+    rectText: SVGElement;
     constructor(trans) {
         super();
         // Create the group element
diff --git a/js/graphics/tragable.ts b/js/graphics/tragable.ts
index e1e6849..458fceb 100644
--- a/js/graphics/tragable.ts
+++ b/js/graphics/tragable.ts
@@ -29,10 +29,10 @@ export class Tragable {
         });
     }
 
-    onMove(cb) {
+    onMove(cb: (event: MouseEvent) => any) {
         this.#moveCB = cb;
     }
-    onClick(cb) {
+    onClick(cb: (event: MouseEvent) => any) {
         this.#clickCB = cb;
     }
 }
\ No newline at end of file