diff --git a/main.c b/main.c
index e6f76e0..3a11c8f 100644
--- a/main.c
+++ b/main.c
@@ -490,17 +490,16 @@ void calculate_simplifications(void)
         lookup[truthtable].cost = cost;
     }
     
-    // create a list of the "done" truthtables
-    struct list {
-        int headtails[N], next[N], head;
-        
-        // for debugging:
-        bool in[N];
+    // create a list truthtables we're done with
+    // and another list of truthtables we're still working on.
+    struct boollist {
+        int _128[2], _64[4], _32[8], _16[16], _8[32], _4[64], _2[128], _1[256];
     } done, undone;
     
-    // init 'done':
-    void init(struct list* this)
+    void init_empty(struct boollist* this)
     {
+        assert(!"TODO");
+        #if 0
         this->head = -1;
         
         for (int i = 0; i < N; i++)
@@ -509,11 +508,18 @@ void calculate_simplifications(void)
             
             this->in[i] = false;
         }
+        #endif
+    }
+
+    void init_full(struct boollist* this)
+    {
+        assert(!"TODO");
     }
     
-    init(&done), init(&undone);
+    assert(!"TODO");
+    // init(&done), init(&undone);
     
-    void insert(struct list* this, int index)
+    void insert(struct boollist* this, uint16_t element)
     {
         assert(!"TODO");
         #if 0
@@ -564,6 +570,11 @@ void calculate_simplifications(void)
         #endif
     }
     
+    void remove(struct boollist* this, uint16_t element)
+    {
+        assert(!"TODO");
+    }
+
     append(W, 0), lookup[W].kind = ek_W;
     append(X, 0), lookup[X].kind = ek_X;
     append(Y, 0), lookup[Y].kind = ek_Y;
@@ -576,6 +587,8 @@ void calculate_simplifications(void)
     {
         uint16_t truthtable = pop();
         
+        assert(!"TODO");
+        #if 0
         insert(truthtable);
         
         int cost = lookup[truthtable].cost;
@@ -780,6 +793,7 @@ void calculate_simplifications(void)
             }
         }
         #endif
+        #endif
     }
 
     if (verbose && print_with_color)