1 files changed, 9 insertions, 129 deletions

diff --git a/src/sequence/sequence.c b/src/sequence/sequence.c
index f3c3b46..78a5aad 100644
--- a/src/sequence/sequence.c
+++ b/src/sequence/sequence.c
@@ -5,74 +5,6 @@
 
 #include "sequence.h"
 
-/*
- * Bypass rendundant ZoO_START_OF_SEQUENCE_ID at the start of a sequence.
- */
-/*@
-   requires
-   (
-      \valid(sequence+ (0 .. sequence_length))
-      || (sequence_length == 0)
-   );
-   requires \separated(sequence, sequence_offset);
-
-   assigns (*sequence_offset);
-
-   ensures (*sequence_offset < sequence_length);
-
-   ensures
-   (
-      (*sequence_offset == 0)
-      || (sequence[0 .. *sequence_offset] == ZoO_START_OF_SEQUENCE_ID)
-   );
-
-   ensures
-   (
-      (*sequence_offset == sequence_length)
-      || (sequence[*sequence_offset + 1] != ZoO_START_OF_SEQUENCE_ID)
-   );
-
-@*/
-static void bypass_redundant_sos
-(
-   const ZoO_index sequence [const restrict],
-   const size_t sequence_length,
-   size_t sequence_offset [const restrict static 1]
-)
-{
-   ZoO_index i;
-
-   *sequence_offset = 0;
-
-   /*@
-      loop invariant 0 <= i <= sequence_length;
-      loop invariant (*sequence_offset <= i);
-      loop invariant
-      (
-         (*sequence_offset == 0)
-         || (sequence[*sequence_offset] == ZoO_START_OF_SEQUENCE_ID)
-      );
-      loop invariant
-         (
-            (i == 0) || (sequence[0 .. (i - 1)] == ZoO_START_OF_SEQUENCE_ID)
-         );
-      loop assigns i, *sequence_offset;
-      loop variant (sequence_length - i);
-   @*/
-   for (i = 0; i < sequence_length; ++i)
-   {
-      if (sequence[i] != ZoO_START_OF_SEQUENCE_ID)
-      {
-         return;
-      }
-      else if (sequence[i] == ZoO_START_OF_SEQUENCE_ID)
-      {
-         *sequence_offset = i;
-      }
-   }
-}
-
-
 /* See "sequence.h" */
 /*@
    requires
@@ -91,80 +23,28 @@ static void bypass_redundant_sos
 @*/
 int ZoO_sequence_cmp
 (
-   const ZoO_index sequence_a [const],
-   size_t sequence_a_length,
-   const ZoO_index sequence_b [const],
-   size_t sequence_b_length
+   const ZoO_index sequence_a [const restrict static 1],
+   const ZoO_index sequence_b [const restrict static 1],
+   const ZoO_index length
 )
 {
-   size_t min_length, a, b;
-   size_t a_offset, b_offset;
-   size_t i;
-   /*@ ghost size_t actual_a_length, actual_b_length; @*/
-
-   bypass_redundant_sos(sequence_a, sequence_a_length, &a_offset);
-   bypass_redundant_sos(sequence_b, sequence_b_length, &b_offset);
+   ZoO_index i, a, b;
 
-   /*@ ghost actual_a_length = sequence_a_length; @*/
-   /*@ ghost actual_b_length = sequence_b_length; @*/
-
-   /*@ assert (a_offset <= sequence_a_length); @*/
-   sequence_a_length -= a_offset;
-   /*@ assert (b_offset <= sequence_b_length); @*/
-   sequence_b_length -= b_offset;
-
-   if (sequence_a_length < sequence_b_length)
-   {
-      min_length = sequence_a_length;
-   }
-   else
+   for (i = 0; i < length; ++i)
    {
-      min_length = sequence_b_length;
-   }
-
-   /*@ assert (min_length <= sequence_a_length); @*/
-   /*@ assert (min_length <= sequence_b_length); @*/
-
-   /*@ assert (min_length + a_offset <= actual_a_length); @*/
-   /*@ assert (min_length + b_offset <= actual_b_length); @*/
-
-   /*@
-      loop invariant 0 <= i <= min_length;
-      loop assigns i;
-      loop variant (min_length - i);
-   @*/
-   for (i = 0; i < min_length; ++i)
-   {
-      /*@ assert ((i + a_offset) < actual_a_length); @*/
-      a = sequence_a[i + a_offset];
-      /*@ assert ((i + b_offset) < actual_b_length); @*/
-      b = sequence_b[i + b_offset];
+      a = sequence_a[i];
+      b = sequence_b[i];
 
       if (a < b)
       {
          return -1;
       }
-      else if (b > a)
+      else if (a > b)
       {
          return 1;
       }
-      else if ((a == ZoO_END_OF_SEQUENCE_ID) && (b == ZoO_END_OF_SEQUENCE_ID))
-      {
-         return 0;
-      }
    }
 
-   if (sequence_a_length > sequence_b_length)
-   {
-      return 1;
-   }
-   else if (sequence_a_length < sequence_b_length)
-   {
-      return -1;
-   }
-   else
-   {
-      return 0;
-   }
+   return 0;
 }