diff --git a/v4/ctx.h b/v4/ctx.h
index 087faa6..36d70db 100644
--- a/v4/ctx.h
+++ b/v4/ctx.h
@@ -7,77 +7,82 @@
 template <class T> class ctx_Controller {
   T context;
   std::list<void *(T)> callbacks;
+  /*
   std::list<T *(T)> functions;
   bool isProcessingQueue = false;
   std::list<T> queue;
+  */
 
-  ctx_Controller(const T &c) {
-    context = c;
-  }
+  public:
+    ctx_Controller(const T &c) {
+      context = c;
+    }
 
-  void executeFunctions() {
-    T c = queue.front();
-    queue.pop_front();
-    for (const auto &f : functions) {
-      T ctx = f(c);
-      if (ctx.recentField != "none") {
-        queue.push_back(ctx);
+    /*
+    void executeFunctions() {
+      T c = queue.front();
+      queue.pop_front();
+      for (const auto &f : functions) {
+        T ctx = f(c);
+        if (ctx.recentField != "none") {
+          queue.push_back(ctx);
+        }
       }
+
+      context.recentField = c.recentField;
+      context.setField(c.recentField, c.field(c.recentField));
+      reportContext();
     }
 
-    context.recentField = c.recentField;
-    context.setField(c.recentField, c.field(c.recentField));
-    reportContext();
-  }
+    void processQueue() {
+      // Decline recursion.
+      if (isProcessingQueue) {
+        return;
+      }
+      isProcessingQueue = true;
+      while (!queue.empty()) {
+        executeFunctions();
+      }
+      isProcessingQueue = false;
+    }
 
-  void processQueue() {
-    // Decline recursion.
-    if (isProcessingQueue) {
-      return;
+    void registerCallback(void (*cb)(T)) {
+      callbacks.push_back(cb);
     }
-    isProcessingQueue = true;
-    while (!queue.empty()) {
-      executeFunctions();
+
+    void registerFieldCallback(const std::string &fieldName, void (*cb)(T)) {
+      auto execCB = [fieldName, cb](T c) {
+        if (c.recentField == fieldName) {
+          cb(c);
+        }
+      };
+      callbacks.push_back(execCB);
     }
-    isProcessingQueue = false;
-  }
 
-  void registerCallback(void (*cb)(T)) {
-    callbacks.push_back(cb);
-  }
+    void registerFunction(T (*f)(T)) {
+      functions.push_back(f);
+    }
 
-  void registerFieldCallback(const std::string &fieldName, void (*cb)(T)) {
-    auto execCB = [fieldName, cb](T c) {
-      if (c.recentField == fieldName) {
-        cb(c);
+    void registerFunctions(const std::list<T *(T)> funcs) {
+      for (const auto &f : funcs) {
+        functions.push_back(f);
       }
-    };
-    callbacks.push_back(execCB);
-  }
-
-  void registerFunction(T (*f)(T)) {
-    functions.push_back(f);
-  }
-
-  void registerFunctions(const std::list<T *(T)> funcs) {
-    for (const auto &f : funcs) {
-      functions.push_back(f);
     }
-  }
 
-  void reportContext() {
-    for (const auto &cb : callbacks) {
-      cb(context);
+    void reportContext() {
+      for (const auto &cb : callbacks) {
+        cb(context);
+      }
     }
-  }
 
-  template <typename U> void set(const std::string &fieldName, const U &value) {
-    T c = context;
-    c.setField(fieldName, value);
-    c.recentField = fieldName;
-    queue.push_back(c);
-    processQueue();
-  }
+    template <typename U> void set(const std::string &fieldName, const U &value) {
+      T c = context;
+      c.setField(fieldName, value);
+      c.recentField = fieldName;
+      queue.push_back(c);
+      processQueue();
+    }
+    */
 };
 
 #endif // ctx_HEADER
diff --git a/v4/ctx_test2.cpp b/v4/ctx_test2.cpp
new file mode 100644
index 0000000..1ca011b
--- /dev/null
+++ b/v4/ctx_test2.cpp
@@ -0,0 +1,36 @@
+#include <string>
+#include "ctx.h"
+#include "memory_Context.h"
+
+std::string ctx_test_Controller_executeFunctions_set() {
+  auto c = memory_createContext();
+  ctx_Controller<memory_Context> ctrl(c);
+  /*
+  // Disable automatic invocation of executeFunctions.
+  ctrl.isProcessingQueue = true;
+  ctrl.set("input", "123");
+
+  auto processInput = [](const memory_Context &c) -> memory_Context {
+    if (c.recentField == "input") {
+      c.outputHelp = "Checked";
+      c.recentField = "outputHelp";
+      return c;
+    }
+    c.recentField = "none";
+    return c;
+  };
+
+  ctrl.registerFunction(processInput);
+  // Apply 'input'.
+  ctrl.executeFunctions();
+  // Apply 'outputHelp'.
+  ctrl.executeFunctions();
+  if (
+    c.input == "123" &&
+    c.outputHelp == "Checked"
+  ) {
+    return "OK: ctx_Controller_executeFunctions_set";
+  }
+  */
+  return "ERR: ctx_Controller_executeFunctions_set";
+}
diff --git a/v4/ctx_test2.h b/v4/ctx_test2.h
new file mode 100644
index 0000000..99230ca
--- /dev/null
+++ b/v4/ctx_test2.h
@@ -0,0 +1,8 @@
+#include <string>
+
+#ifndef ctx_test_HEADER
+#define ctx_test_HEADER
+
+std::string ctx_test_Controller_executeFunctions_set();
+
+#endif // ctx_test_HEADER
diff --git a/v4/main.cpp b/v4/main.cpp
index 3a4c0ce..05bac98 100644
--- a/v4/main.cpp
+++ b/v4/main.cpp
@@ -1,11 +1,14 @@
 #include <iostream>
 #include <string>
 #include <vector>
+#include "ctx_test2.h"
 #include "main.h"
 #include "memory_Context.h"
 
 int main() {
   std::cout
+    << ctx_test_Controller_executeFunctions_set()
+    << std::endl
     << llm_test_isDigit_digit()
     << std::endl
     << llm_test_isDigit_notDigit()