// main.c - Main program that uses symbols from math.c

#include <stdio.h>

// Define the external symbol that math.c references
int usrid = 42;

// Declare functions from math.c that we want to use
extern int square(int x);
extern int pick_prime();
extern int get_n();
extern void show_values();

// Declare global variables from math.c
extern int pi;
extern int e;

// Note: We cannot access 'randomval' or 'is_prime' from math.c 
// because they are declared as static (local to math.c)

int main() {
    printf("=== Symbol Linkage Demonstration ===\n\n");
    
    printf("1. Accessing global symbols from math.c:\n");
    printf("   pi = %d\n", pi);
    printf("   e = %d\n", e);
    
    printf("\n2. Calling global functions from math.c:\n");
    printf("   square(7) = %d\n", square(7));
    printf("   pick_prime() = %d\n", pick_prime());
    printf("   get_n() = %d\n", get_n());
    
    printf("\n3. Demonstrating symbol resolution:\n");
    show_values();
    
    printf("\n4. Modifying global symbols:\n");
    pi = 314;  // Modify global variable from math.c
    printf("   Modified pi to 314\n");
    printf("   pi is now = %d\n", pi);
    
    return 0;
}