diff --git a/build.bat b/build.bat
index 18c6e2a..6280fbd 100644
--- a/build.bat
+++ b/build.bat
@@ -3,11 +3,14 @@
 ctime -begin timeBuild.ctm
 
 set CommonCompilerFlags=/nologo /Zi /FC /WX /W4 /wd4201 /wd4100 /wd4189 /wd4244 /wd4127 /wd4456
-set Sources=../src/main.c
+@rem set Sources=../src/main.c
+@rem set OutputName=program.exe
+set Sources=../src/algorithms_main.c
+set OutputName=algorithms_test.exe
 
 IF NOT EXIST .\build mkdir .\build
 pushd .\build
-cl  %CommonCompilerFlags% %Sources% -Feprogram.exe
+cl  %CommonCompilerFlags% %Sources% -Fe%OutputName%
 set LastError=%ERRORLEVEL%
 popd
 
diff --git a/build/algorithms_test.rdi b/build/algorithms_test.rdi
new file mode 100644
index 0000000..07e5098
Binary files /dev/null and b/build/algorithms_test.rdi differ
diff --git a/run.bat b/run.bat
index 6920322..752c0f1 100644
--- a/run.bat
+++ b/run.bat
@@ -1,4 +1,5 @@
 @echo off
 pushd build
-call program.exe
+@rem call program.exe
+call algorithms_test.exe
 popd
diff --git a/src/algorithms_main.c b/src/algorithms_main.c
new file mode 100644
index 0000000..23d6f0a
--- /dev/null
+++ b/src/algorithms_main.c
@@ -0,0 +1,104 @@
+// header includes
+#include "base/base_inc.h"
+#include "os/os_inc.h"
+
+// .c includes
+#include "base/base_inc.c"
+#include "os/os_inc.c"
+#include "os/os_entry_point.c"
+
+#define LOG DebugPrintf
+function void 
+DebugPrintf(const char* format, ...)
+{
+    char buffer[4096];
+    va_list args;
+    va_start(args, format);
+    vsprintf_s(buffer, sizeof(buffer), format, args);
+    OutputDebugString(buffer);
+    va_end(args);
+}
+
+typedef struct F64Node F64Node;
+struct F64Node 
+{
+  F64Node *prev;
+  F64Node *next;
+  F64 value;
+};
+
+typedef struct F64List F64List;
+struct F64List
+{
+  F64Node *first;
+  F64Node *last;
+  U32 length;
+};
+
+F64Node g_f64_nil_node = {0};
+
+function void
+F64_push_node(F64List *list, F64Node *n)
+{
+  if(list->first == 0)
+  {
+    list->first = n;
+    list->last = n;
+  } else {
+    list->last->next = n;
+    list->last = n;
+  }
+  list->length += 1;
+}
+
+function void
+F64_push(Arena *arena, F64List *list, F64 value) 
+{
+  F64Node *node = PushArrayZero(arena, F64Node, 1);
+  node->value = value;
+  F64_push_node(list, node);
+}
+
+function void
+print_F64_ll(F64List *list)
+{
+  for(F64Node *n = list->first; n != 0; n = n->next)
+  {
+    LOG(" %2.f \n", n->value);
+  }
+}
+
+function void
+reverse_linked_list_lol(void)
+{
+  Arena *ll_arena = m_make_arena();
+  F64List list = {0};
+  for (U32 i = 0; i < 10; i++) 
+  {
+    F64_push(ll_arena, &list, (F64)i);
+  }
+
+  print_F64_ll(&list);
+
+  F64Node *prev = 0;
+  F64Node *current = list.first;
+  F64Node *next_temp = 0;
+  while(current != 0) 
+  {
+    next_temp = current->next;
+    current->next = prev;
+    prev = current;
+    current = next_temp;
+  }
+  list.first = prev;
+   
+  print_F64_ll(&list);
+}
+
+
+
+void
+EntryPoint(void) 
+{
+  reverse_linked_list_lol();
+}
diff --git a/src/base/base_core.h b/src/base/base_core.h
index 91fd56f..dbf3b67 100644
--- a/src/base/base_core.h
+++ b/src/base/base_core.h
@@ -102,13 +102,13 @@
 // f, l, n are "first", "last", "node" I think?
 // DLL
 // Doubly Linked List: Each node has a prev and next pointer. Operations: Push back, Push front, remove
-#define DLLInsert_NPZ(f,l,p,n,next,prev,zchk,zset) \
-(zchk(f) ? (((f) = (l) = (n)), zset((n)->next), zset((n)->prev)) :\
-zchk(p) ? (zset((n)->prev), (n)->next = (f), (zchk(f) ? (0) : ((f)->prev = (n))), (f) = (n)) :\
+#define DLLInsert_NPZ(f,l,p,n,next,prev,zchk,SetNull) \
+(zchk(f) ? (((f) = (l) = (n)), SetNull((n)->next), SetNull((n)->prev)) :\
+zchk(p) ? (SetNull((n)->prev), (n)->next = (f), (zchk(f) ? (0) : ((f)->prev = (n))), (f) = (n)) :\
 ((zchk((p)->next) ? (0) : (((p)->next->prev) = (n))), (n)->next = (p)->next, (n)->prev = (p), (p)->next = (n),\
 ((p) == (l) ? (l) = (n) : (0))))
 
-#define DLLPushBack_NPZ(f,l,n,next,prev,zchk,zset) DLLInsert_NPZ(f,l,l,n,next,prev,zchk,zset)
+#define DLLPushBack_NPZ(f,l,n,next,prev,zchk,SetNull) DLLInsert_NPZ(f,l,l,n,next,prev,zchk,SetNull)
 
 #define DLLPushBack_NP(f, l, n, next, prev, zchk) \
 (zchk(f) ? ((f)=(l)=(n),(n)->next=(n)->prev=0) : ((n)->prev=(l),(l)->next=(n),(l)=(n),(n)->next=0))
@@ -124,10 +124,10 @@ zchk(p) ? (zset((n)->prev), (n)->next = (f), (zchk(f) ? (0) : ((f)->prev = (n)))
 ((n)->next->prev=(n)->prev, \
 (n)->prev->next=(n)->next) ))
 
-#define DLLRemove_NPZ(f,l,n,next,prev,zchk,zset) (((f)==(n))?\
-((f)=(f)->next, (zchk(f) ? (zset(l)) : zset((f)->prev))):\
+#define DLLRemove_NPZ(f,l,n,next,prev,zchk,SetNull) (((f)==(n))?\
+((f)=(f)->next, (zchk(f) ? (SetNull(l)) : SetNull((f)->prev))):\
 ((l)==(n))?\
-((l)=(l)->prev, (zchk(l) ? (zset(f)) : zset((l)->next))):\
+((l)=(l)->prev, (zchk(l) ? (SetNull(f)) : SetNull((l)->next))):\
 ((zchk((n)->next) ? (0) : ((n)->next->prev=(n)->prev)),\
 (zchk((n)->prev) ? (0) : ((n)->prev->next=(n)->next))))
 
@@ -143,17 +143,17 @@ zchk(p) ? (zset((n)->prev), (n)->next = (f), (zchk(f) ? (0) : ((f)->prev = (n)))
 ////////////////
 // Queue
 // Queue has only a next pointer. But we can push from front also.
-// zchk = zero check, zset = zero set
-#define QueuePush_NZ(f, l, n, next, zchk, zset) (zchk(f)?\
-(((f)=(l)=(n)), zset((n)->next)):\
-((l)->next=(n),(l)=(n),zset((n)->next)))
+// zchk = zero check, SetNull = zero set
+#define QueuePush_NZ(f, l, n, next, zchk, SetNull) (zchk(f)?\
+(((f)=(l)=(n)), SetNull((n)->next)):\
+((l)->next=(n),(l)=(n),SetNull((n)->next)))
 
-#define QueuePushFront_NZ(f, l, n, next, zchk, zset) ( zchk(f) ? \
-((f)=(l)=(n)), zset((n)->next) :  \
+#define QueuePushFront_NZ(f, l, n, next, zchk, SetNull) ( zchk(f) ? \
+((f)=(l)=(n)), SetNull((n)->next) :  \
 ((n)->next = (f)), ((f) = (n)) ) 
 
-#define QueuePop_NZ(f, l, next, zchk, zset) ( (f)==(l) ? \
-(zset(f), zset(l)) : ((f)=(f)->next))
+#define QueuePop_NZ(f, l, next, zchk, SetNull) ( (f)==(l) ? \
+(SetNull(f), SetNull(l)) : ((f)=(f)->next))
 
 #define QueuePush(f, l, n) QueuePush_NZ(f, l, n, next, CheckNull, SetNull)
 #define QueuePushFront(f, l, n) QueuePushFront_NZ(f, l, n, next, CheckNull, SetNull)