Question: I'm using ruby motion. Below are the details of my environment. 

```
$ motion --version
2.9
$ bundle
Using bubble-wrap (1.4.0) 
Using motion-require (0.0.7) 
Using formotion (1.6) 
Using motion-layout (0.0.1) 
Using thor (0.18.1) 
Using rubymotion_generators (0.1.0) 
Using bundler (1.3.5) 

```

When I run my app and click a button that is suppose to load a form built with formation, my app abruptly crashes with this error message. 

> 
> *\** Simulator session ended with error: Error Domain=DTiPhoneSimulatorErrorDomain Code=1 "The simulated application
>  quit." UserInfo=0x10011e200 {NSLocalizedDescription=The simulated
>  application quit., DTiPhoneSimulatorUnderlyingErrorCodeKey=-1}
> 
> 
> 

Running with `rake debug=1` I see the following:

```
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0xc7243c89
0x0081309f in objc_msgSend ()
(gdb) 

```

My app was working perfectly fine before upgrading rubymotion and once I updated rubymotion I had to update some of my gems as well. 

How can I resolve this or troubleshoot this?

Answer: 
Parenthesis are not used for multiplication in Java as they are in mathematics. Use the `*` operator.

```
if (((i - posX) * (i - posX) + (j - posY) * (j - posY)) == (radius) * (radius)) {

```

Read: [Operators](http://docs.oracle.com/javase/tutorial/java/nutsandbolts/operators.html)
you forgot to use multiplicate operator \*

check:

`if ( ( (i-posX)*(i-posX) + (j-posY)*(j-posY) ) == (radius*radius) )`