Sharing Variables Between Cores

I don't understand how to share variables between cores on the ShieldBuddy, even after reading the user manual.  This is a simple program trying to understand it, however it doesn't work.  Can someone show me what I'm doing wrong or post an example.  This is the error message when compiling - " 'c' was not declared in this scope".

Chuck





/*** Core 0 ***/
void setup() {
 // put your setup code for core 0 here, to run once:

SerialASC.begin(9600);

}

void loop() {
 // put your main code for core 0 here, to run repeatedly:

delay(5); /* Make it look like this core is doing something useful! */

/* If ASC is free lock it */
while(Htx_LockResource(&SerialASC.PortInUse) == Htx_RESOURCE_BUSY) { ; }
SerialASC.println(c);

Htx_UnlockResource(&SerialASC.PortInUse);

}


/*** Core 1 ***/
void setup1() {
 
}

void loop1() {
 // put your main code for core 1 here, to run repeatedly:

 int a = 10;
 int b = 13;
 int c = a + b;

while(Htx_LockResource(&SerialASC.PortInUse) == Htx_RESOURCE_BUSY) { ; }

Htx_UnlockResource(&SerialASC.PortInUse);

}


/*** Core 2 ***/
void setup2() {
 // put your setup code for core 2 here, to run once:


}

void loop2() {
 // put your main code for core 2 here, to run repeatedly:

delay(25); /* Make it look like this core is doing something useful! */

while(Htx_LockResource(&SerialASC.PortInUse) == Htx_RESOURCE_BUSY) { ; }

//SerialASC.print("Hello from Core 2\n\r");

Htx_UnlockResource(&SerialASC.PortInUse);

}