diff --git a/src/cap12/pthreads-factorial.cpp b/src/cap12/pthreads-factorial.cpp
index f445ba1..876fd55 100644
--- a/src/cap12/pthreads-factorial.cpp
+++ b/src/cap12/pthreads-factorial.cpp
@@ -55,14 +55,14 @@ int main()
 
     if (return_code)
     {
-        fmt::print( stderr, "Error ({}) al crear el hilo: {}\n", return_code, strerror(return_code) );
+        fmt::print( stderr, "Error ({}) al crear el hilo: {}\n", return_code, std::strerror(return_code) );
         return EXIT_FAILURE;
     }
 
     return_code = pthread_create( &thread2, nullptr,  factorial_thread, &thread2_args );
     if (return_code)
     {
-        fmt::print( stderr, "Error ({}) al crear el hilo: {}\n", return_code, strerror(return_code) );
+        fmt::print( stderr, "Error ({}) al crear el hilo: {}\n", return_code, std::strerror(return_code) );
         
         // Al terminar main() aquí, estaremos abortando la ejecución del primer hilo, si no ha terminado antes.
         // Este caso es muy sencillo, así que no importa. Pero no suele ser buena idea no dejar que los hilos tengan
diff --git a/src/cap12/threads-factorial.cpp b/src/cap12/threads-factorial.cpp
index ce2e314..e51d9e5 100644
--- a/src/cap12/threads-factorial.cpp
+++ b/src/cap12/threads-factorial.cpp
@@ -9,11 +9,11 @@
 //
 
 #include <iostream>
-#include <sstream>
 #include <thread>
 
 #define FMT_HEADER_ONLY
 #include <fmt/format.h> // Hasta que std::format (C++20) esté disponible
+#include <fmt/std.h>
 
 #include <common/bigint_factorial.hpp>
 
@@ -22,16 +22,6 @@ void factorial_thread (BigInt& result, BigInt number, BigInt lower_bound)
     result = calculate_factorial( number, lower_bound );
 }
 
-void print_thread_info(std::thread& thread)
-{
-    std::stringstream ss;
-    ss << thread.get_id();
-    fmt::print( "Hilo creado: {} (0x{:x})\n",
-        ss.str(),
-        reinterpret_cast<uintptr_t>(thread.native_handle())
-    );
-}
-
 int main()
 {
     auto number = get_user_input();
@@ -43,10 +33,10 @@ int main()
     auto thread2_number = thread1_lower_bound - 1;
 
     std::thread thread1(factorial_thread, std::ref(thread1_result), number, thread1_lower_bound);
-    print_thread_info(thread1);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread1.get_id(), thread1.native_handle() );
 
     std::thread thread2(factorial_thread, std::ref(thread2_result), thread2_number, 2);
-    print_thread_info(thread2);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread2.get_id(), thread2.native_handle() );
 
     // Esperar a que los hilos terminen antes de continuar.
     // Si salimos de main() sin esperar, el proceso terminará y todos los hilos morirán inmediatamente,
diff --git a/src/cap13/threads-sync-counter.cpp b/src/cap13/threads-sync-counter.cpp
index 1d165d5..db16d84 100644
--- a/src/cap13/threads-sync-counter.cpp
+++ b/src/cap13/threads-sync-counter.cpp
@@ -9,11 +9,11 @@
 
 #include <iostream>
 #include <mutex>
-#include <sstream>
 #include <thread>
 
 #define FMT_HEADER_ONLY
 #include <fmt/format.h> // Hasta que std::format (C++20) esté disponible
+#include <fmt/std.h>
 
 struct increment_counter_thread_args
 {
@@ -37,26 +37,16 @@ void increment_counter (increment_counter_thread_args& args)
     fmt::print( "Valor del contador: {}\n", args.counter );
 }
 
-void print_thread_info(std::thread& thread)
-{
-    std::stringstream ss;
-    ss << thread.get_id();
-    fmt::print( "Hilo creado: {} (0x{:x})\n",
-        ss.str(),
-        reinterpret_cast<uintptr_t>(thread.native_handle())
-    );
-}
-
 int main()
 {
     increment_counter_thread_args thread_args = { .counter = 0 };
 
     // Crear algunos hilos independientes cada uno de los cuales ejecutará increment_counter()    
     std::thread thread1(increment_counter, std::ref(thread_args));
-    print_thread_info(thread1);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread1.get_id(), thread1.native_handle() );
 
     std::thread thread2(increment_counter, std::ref(thread_args));
-    print_thread_info(thread2);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread2.get_id(), thread2.native_handle() );
 
     // Esperar a que los hilos terminen antes de continuar.
     // Si salimos de main() sin esperar, el proceso terminará y todos los hilos morirán inmediatamente,
diff --git a/src/cap13/threads-sync-factorial.cpp b/src/cap13/threads-sync-factorial.cpp
index 2c3031c..90b6d26 100644
--- a/src/cap13/threads-sync-factorial.cpp
+++ b/src/cap13/threads-sync-factorial.cpp
@@ -14,12 +14,12 @@
 #include <functional>
 #include <mutex>
 #include <numeric>
-#include <sstream>
 #include <thread>
 #include <vector>
 
 #define FMT_HEADER_ONLY
 #include <fmt/format.h> // Hasta que std::format (C++20) esté disponible
+#include <fmt/std.h>
 
 #include <common/bigint_factorial.hpp>
 
@@ -39,16 +39,6 @@ void factorial_thread (factorial_thread_results& results, BigInt number, BigInt
     // El mutex se desbloquea al destruirse 'lock'
 }
 
-void print_thread_info(std::thread& thread)
-{
-    std::stringstream ss;
-    ss << thread.get_id();
-    fmt::print( "Hilo creado: {} (0x{:x})\n",
-        ss.str(),
-        reinterpret_cast<uintptr_t>(thread.native_handle())
-    );
-}
-
 int main()
 {
     auto number = get_user_input();
@@ -60,10 +50,10 @@ int main()
     auto thread2_number = thread1_lower_bound - 1;
 
     std::thread thread1(factorial_thread, std::ref(thread_results), number, thread1_lower_bound);
-    print_thread_info(thread1);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread1.get_id(), thread1.native_handle() );
 
     std::thread thread2(factorial_thread, std::ref(thread_results), thread2_number, 2);
-    print_thread_info(thread2);
+    fmt::print( "Hilo creado: {} (0x{:x})\n", thread2.get_id(), thread2.native_handle() );
 
     // Esperar a que los hilos terminen antes de continuar.
     // Si salimos de main() sin esperar, el proceso terminará y todos los hilos morirán inmediatamente,
diff --git a/src/cap13/threads-sync-semaphore.cpp b/src/cap13/threads-sync-semaphore.cpp
index 758addb..f5048a3 100644
--- a/src/cap13/threads-sync-semaphore.cpp
+++ b/src/cap13/threads-sync-semaphore.cpp
@@ -7,32 +7,33 @@
 //      g++ -I../ -I../../lib -o threads-sync-semaphore threads-sync-semaphore.cpp
 //
 
-#include <thread>
 #include <iostream>
 #include <vector>
+#include <thread>
 
 #define FMT_HEADER_ONLY
 #include <fmt/format.h> // Hasta que std::format (C++20) esté disponible
 
 #include "semaphore.hpp"
 
-void thread_func(semaphore& sem, int thread_id)
+void thread_function(semaphore& sem, int thread_id)
 {
     sem.acquire();
-    fmt::print( "Hilo {} creado\n", thread_id);
-    std::this_thread::sleep_for(std::chrono::seconds(2)); // Dormir el hilo para simular trabajo
-    fmt::print( "Hilo {} terminado\n", thread_id);
+    fmt::print( "Hilo {} creado\n", thread_id );
+    std::this_thread::sleep_for( std::chrono::seconds(2) ); // Dormir el hilo para simular trabajo
+    fmt::print( "Hilo {} terminado\n", thread_id );
     sem.release();
 }
 
-int main() {
+int main()
+{
     const int num_threads = 10;
     semaphore sem(3); // Solo permitir 3 hilos simultáneos
 
     std::vector<std::thread> threads;
     for(int i = 0; i < num_threads; i++)
     {
-        threads.push_back(std::thread(thread_func, std::ref(sem), i));
+        threads.push_back( std::thread( thread_function, std::ref(sem), i ));
     }
 
     for(auto& t : threads)