diff --git a/xo-interpreter/include/xo/interpreter/VirtualSchematikaMachine.hpp b/xo-interpreter/include/xo/interpreter/VirtualSchematikaMachine.hpp
index 94712f33..9df2755f 100644
--- a/xo-interpreter/include/xo/interpreter/VirtualSchematikaMachine.hpp
+++ b/xo-interpreter/include/xo/interpreter/VirtualSchematikaMachine.hpp
@@ -68,7 +68,7 @@ namespace xo {
             void execute_one();
 
             /** interpret literal constant expression **/
-            void constant_op();
+            void eval_constant_op();
 
             /** goto error state with message @p err **/
             void report_error(const std::string & err);
diff --git a/xo-interpreter/src/interpreter/VirtualSchematikaMachine.cpp b/xo-interpreter/src/interpreter/VirtualSchematikaMachine.cpp
index 9353c3be..64b29b5a 100644
--- a/xo-interpreter/src/interpreter/VirtualSchematikaMachine.cpp
+++ b/xo-interpreter/src/interpreter/VirtualSchematikaMachine.cpp
@@ -127,7 +127,7 @@ namespace xo {
 
                     switch (expr_->extype()) {
                     case exprtype::constant:
-                        this->constant_op();
+                        this->eval_constant_op();
                         break;
 
                     case exprtype::invalid:
@@ -169,7 +169,7 @@ namespace xo {
         }
 
         void
-        VirtualSchematikaMachine::constant_op()
+        VirtualSchematikaMachine::eval_constant_op()
         {
             using xo::scm::ConstantInterface;
 
@@ -213,6 +213,8 @@ namespace xo {
             /** remembers promised variable type **/
             env_->establish_var(expr->lhs_variable());
 
+
+
             /* lhs_var
              * rhs
              */