diff --git a/CMakeLists.txt b/CMakeLists.txt
index eacaffe..30250a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,10 +2,35 @@ cmake_minimum_required(VERSION 3.5)
 
 project(elysius NONE)
 
-option(BUILD_MENU "Add the Main Menu" ON)
+option(BUILD_MENU "Add the Main Menu"                   ON)
+option(BUILD_CSTN "Include constants collection"        ON)
+option(BUILD_CHIM "Include chemical equations analyser" ON)
+option(BUILD_PRDQ "Include periodic elements table"     ON)
+option(BUILD_CONV "Include units conversion program"    ON)
+option(BUILD_ELEC "Include electronic circuits solver"  ON)
 
 add_subdirectory(srcs)
 
+if(BUILD_CSTN)
+    set(DEFINITION "${DEFINITION} -DCONSTANT") 
+endif()
+
+if(BUILD_CHIM)
+    set(DEFINITION "${DEFINITION} -DCHEMISTRY") 
+endif()
+
+if(BUILD_PRDQ)
+    set(DEFINITION "${DEFINITION} -DPERIODIC") 
+endif()
+
+if(BUILD_CONV)
+    set(DEFINITION "${DEFINITION} -DCONVERT") 
+endif()
+
+if(BUILD_ELEC)
+    set(DEFINITION "${DEFINITION} -DCIRCUIT") 
+endif()
+
 add_custom_target(menu ALL)
 find_program(FOO_EXECUTABLE foo)
 function(preprocess_foo out_var)
@@ -14,7 +39,7 @@ function(preprocess_foo out_var)
     add_custom_command(
       PRE_BUILD
       TARGET menu
-      COMMAND cd ${PROJECT_SOURCE_DIR} && ./pithon.sh srcs/${in_f}
+      COMMAND cd ${PROJECT_SOURCE_DIR} && ./pithon.sh srcs/${in_f} ${DEFINITION}
       DEPENDS srcs/${in_f}
       COMMENT "Creating preprocessed foo file ${in_f}"
       VERBATIM
diff --git a/pithon.sh b/pithon.sh
index db6dc7d..a396e77 100755
--- a/pithon.sh
+++ b/pithon.sh
@@ -11,6 +11,8 @@ out="${1/.cbs/.txt}";
 
 # TODO :
 
+echo $2
+
 word='a-zA-Z0-9_';
 
 cat "$1" | sed 's/^[ \t]*//;s/[ \t]*$//' > "$out.tmp";
@@ -51,7 +53,7 @@ sed -e 's/\xe2\x88\x9a/sqrt/g' -e 's/\xe2\x88\x87/nabla/g;s/\xe2\x88\x80/for/g'
 #sed -i -e "s/\[ *\([$word]*\) *; *\([$word]*\) *\]/range(\1,\2+1)/g" "$out";
 #sed -i -e "s/\] *\([$word]*\) *; *\([$word]*\) *\]/range(\1+1,\2+1)/g" "$out";
 
-cpp "$out" > "$out.tmp";
+cpp "$out" $2 > "$out.tmp";
 
 sed '/^#/ d' "$out.tmp" > "$out" && rm "$out.tmp";
 sed -i 's/#.*$//;/^$/d' "$out";
@@ -62,4 +64,4 @@ sed -i 's/\xe2\x9f\xa9/]/g;s/\xe2\x9f\xa8/[/g' "$out";
 
 python3 g1mtool.py pack "$out"
 
-rm "$out";
\ No newline at end of file
+#rm "$out";
\ No newline at end of file
diff --git a/srcs/0~MENU__.cbs b/srcs/0~MENU__.cbs
index acda54c..3b3b546 100644
--- a/srcs/0~MENU__.cbs
+++ b/srcs/0~MENU__.cbs
@@ -1,15 +1,7 @@
-#define PERIODIC  0
-#define CONSTANT  1
-#define CONVERT   0
-#define CHEMISTRY 0
-#define CIRCUIT   0
-
 #include "../preproc/error_codes.def"
 
 Local i
-AxesOff
-GridOff
-LabelOff
+AxesOff:GridOff:LabelOff
 ViewWindow 1,127,0,1,63,0
 Lbl 1
 Cls
@@ -37,7 +29,7 @@ For 2→i To 92 Step 30
 //  IfEnd
 Next
 
-#if defined(PERIODIC) && (PERIODIC == 1)
+#if defined(PERIODIC)
     F-Line 2,40,2,49:
     F-Line 4,40,4,49:
     F-Line 6,40,6,49:
@@ -98,7 +90,7 @@ Next
     FillRect 2,8,30,25
 #endif
 
-#if defined(CONSTANT) && (CONSTANT == 1)
+#if defined(CONSTANT)
     F-Line 33,50,35,50:
     F-Line 36,49,38,49:
     F-Line 39,48,41,46:
@@ -159,7 +151,7 @@ Next
     FillRect 32,8,60,25
 #endif
 
-#if defined(CONVERT) && (CONVERT == 1)
+#if defined(CONVERT)
     F-Line 62,53,62,55:
     F-Line 63,52,64,52:
     F-Line 63,56,64,56:
@@ -230,7 +222,7 @@ Next
     FillRect 62,8,90,25
 #endif
 
-#if defined(CHEMISTRY) && (CHEMISTRY == 1)
+#if defined(CHEMISTRY)
     F-Line 92,52,92,56:
     F-Line 93,52,94,52:
     F-Line 93,54,94,54:
@@ -295,7 +287,7 @@ Next
     FillRect 92,8,120,25
 #endif
 
-#if defined(CIRCUIT) && (CIRCUIT == 1)
+#if defined(CIRCUIT)
     Text 27,2,"CIRCUIT":
     F-Line 3,30,15,30:
     F-Line 15,31,18,31:
@@ -337,7 +329,7 @@ LocateYX 0,38,"MAIN MENU"
 Lbl 2
 Prog "_WAITKEY"→i
 Switch i:
-#   if defined(PERIODIC) && (PERIODIC == 1)
+#   if defined(PERIODIC)
         Case 72:
             Try :
                 Prog "PER~MAIN"
@@ -346,7 +338,7 @@ Switch i:
             TryEnd
             Goto 1
 #   endif
-#   if defined(CONSTANT) && (CONSTANT == 1)
+#   if defined(CONSTANT)
         Case 62:
             Try :
                 Prog "CST~MAIN"
@@ -355,7 +347,7 @@ Switch i:
             TryEnd
             Goto 1
 #   endif
-#   if defined(CONVERT) && (CONVERT == 1)
+#   if defined(CONVERT)
         Case 52:
             Try :
                 Prog "CNV~MAIN"
@@ -364,7 +356,7 @@ Switch i:
             TryEnd
             Goto 1
 #       endif
-#   if defined(CHEMISTRY) && (CHEMISTRY == 1)
+#   if defined(CHEMISTRY)
         Case 73:
             Try :
                 Prog "CHM~MAIN"
@@ -373,7 +365,7 @@ Switch i:
             TryEnd
             Goto 1
 #   endif
-#   if defined(CIRCUIT) && (CIRCUIT == 1)
+#   if defined(CIRCUIT)
         Case 63:
             Try :
                 Prog "ELC~MAIN"
@@ -388,4 +380,4 @@ Switch i:
         ClrText
         Stop
 SwitchEnd
-        Goto 2
+Goto 2