--- capa/capa51/pProj/capaUnit.c	2000/08/22 18:01:19	1.8
+++ capa/capa51/pProj/capaUnit.c	2004/03/26 20:02:03	1.12
@@ -781,17 +781,17 @@ int  check_correct_unit(char *u_symb,Uni
 	  (Pstack[Ptopidx]->u_count == t->u_count) ) { /* has unit */
 	*scale = units_ratio(Pstack[Ptopidx], t);
 	if( *scale == 0.0 ) {
-	  result = UNIT_FAIL;
+	  result = UNIT_IRRECONCIBLE;
 	}
 	free_utree(ap);
       } else {
-	result = UNIT_FAIL;
+	result = UNIT_INVALID_STUDENT3;
       }
     } else { /* invalid unit representation */
-      result = UNIT_FAIL;
+      result = UNIT_INVALID_STUDENT2;
     }
   } else {
-    result = UNIT_FAIL;
+    result = UNIT_INVALID_STUDENT1;
   }
 #ifdef UNIT_DBUG
   fclose(ufp);
@@ -912,8 +912,9 @@ u_copy_unit(Unit_t *a_p, Unit_t *b_p, do
       a_p->u_count++;
     } else if( b_p->u_type == U_DERIVED) {
       /* derived units but without any units elements (scalar) */
-      /* do nothing, ignore this units  WE REALLY MEAN THIS DON'T DO THE NEXT LINE!*/
       /*a_p->u_count++;*/
+      scale = pow(b_p->u_scale, exp_scale);
+      a_p->u_scale = a_p->u_scale * scale;
     } else if( b_p->u_type == U_CONSTANT ) {
       scale = pow(b_p->u_scale, exp_scale);
       a_p->u_scale = a_p->u_scale * scale;
@@ -1407,10 +1408,10 @@ u_insert_derived(n_p,s_p,c_p,u_p)char  *
   strcpy(new_p->u_comment,c_p);
   
   simplify_unit(new_p);
-  /*
+#ifdef UNIT_DBUG
   printf("Derived Unit:%s\n",new_p->u_name);
   print_unit_t(new_p); 
-  */
+#endif
   if (c_result < 0 ) {
     new_p->u_left = t->u_left; new_p->u_right = t;
     t->u_left = NULL;
@@ -1743,18 +1744,18 @@ p_new_unit(Unit_t *left_p, Unit_t *right
             err_code = 3;
 	    cu_p->u_type   = U_UNKNOWN;
           }
-        } else {
+        } else { /* symb_str is not in <prefix><units> form */
           /* printf("<<%s>>", symb_str); */
           err_code = 2;
 	  cu_p->u_type   = U_UNKNOWN;
         }
       } else {/* len == 1 */
-        /* printf(" not found\n"); */
+        /* printf(" not found in symbol tree \n"); */
         err_code = 1;
 	cu_p->u_type   = U_UNKNOWN;
       }
     }
-  } else {
+  } else { /* why would we have a length less than zero symb_str ? */
     err_code = 4;
   }