fn main(): Unit = {
    Console.print("=== Allocation Comparison ===")
    
    // FBIP path (rc=1): list is reused
    Console.print("Test 1: FBIP path")
    let a1 = List.range(1, 50)
    let b1 = List.map(a1, fn(x: Int): Int => x * 2)
    let c1 = List.reverse(b1)
    Console.print("FBIP done")
    
    // To show non-FBIP, we need concat which doesn't have FBIP
    Console.print("Test 2: Non-FBIP path (concat)")
    let x = List.range(1, 25)
    let y = List.range(26, 50)
    let z = List.concat(x, y)  // concat always allocates new
    Console.print("Concat done")
}