In Objective-C, lowercase letters are significant.
main is where program execution begins.
Open and closed braces enclose program statements in a routine.
All program statements must be terminated by a semicolon.

#import <Foundation/Foundation.h>

int main (int argc, const char *argv[])
{
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
   int i;

   i = 1;
   NSLog (@"Testing...");
   NSLog (@"....%i", i);
   NSLog (@"...%i", i + 1);
   NSLog (@"..%i", i + 2);

   [pool drain];
   return 0;
}

#import <Foundation/Foundation.h>

int main (int argc, const char *argv[]);
(
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

   INT sum;
   /* COMPUTE RESULT //
   sum = 25 + 37 - 19
   / DISPLAY RESULTS /
   NSLog (@'The answer is %i' sum);

   [pool drain];
   return 0;
}

#import <Foundation/Foundation.h>

int main (int argc, const char *argv[])
{
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
   int answer, result;

   answer = 100;
   result = answer - 10;

   NSLog (@"The result is %i\n", result + 5);

   [pool drain];
   return 0;
}