correction on promela model to follow indications in the assignment

ReversalModel/reversal.pml.m4

@@ -5,9 +5,9 @@ define(`for',`ifelse($#,0,``$0'',`ifelse(eval($2<=$3),1,
     `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')
 */
 
-int to_reverse[LENGTH]; // array to reverse
+int a[LENGTH]; // array to reverse
-int reversed_seq[LENGTH]; // for SequentialReverser: where the reverse is stored 
+int r_s[LENGTH]; // for SequentialReverser: where the reverse is stored 
-int reversed_par[LENGTH]; // for ParallelReverser: where the reverse is stored
+int r_p[LENGTH]; // for ParallelReverser: where the reverse is stored
 
 // stores termination of each reverser
 // index 0 is for the sequential algorithm
@@ -22,42 +22,26 @@ proctype ThreadedReverser(int from; int to; int n) {
 
     int k;
     for (k: from .. (to - 1)) {
-        printf("reversed_par[%d] = to_reverse[%d]\n", LENGTH - k - 1, k);
+        printf("r_p[%d] = a[%d]\n", LENGTH - k - 1, k);
-        reversed_par[LENGTH - k - 1] = to_reverse[k];
+        r_p[LENGTH - k - 1] = a[k];
     }
 
     printf("proc[%d]: ended\n", n);
     done[n] = true;
 }
 
-init {
-    printf("program start\n");
-    // array initialization
-    {
-        int i;
-        for (i in to_reverse) {
-            int value;
-            select(value: 0 .. R);
-            to_reverse[i] = value;
-            printf("to_reverse[%d]: %d\n", i, value);
-        }
-    }
-
-    printf("sequential start\n");
 // SequentialReverser implementation
-    {
+proctype SequentialReverser() {
     int k;
     for (k: 0 .. (LENGTH - 1)) {
-            reversed_seq[LENGTH - k - 1] = to_reverse[k];
+        r_s[LENGTH - k - 1] = a[k];
-            printf("reversed_seq[%d] = to_reverse[%d]\n", LENGTH - k - 1, k);
+        printf("r_s[%d] = a[%d]\n", LENGTH - k - 1, k);
     }
     done[0] = true; // mark sequential end
 }
-    printf("sequential end\n");
 
-    printf("parallel start\n");
 // ParallelReverser implementation
-    {
+proctype ParallelReverser() {
     int n;
     int s = LENGTH / N;
     
@@ -78,14 +62,34 @@ init {
         printf("[%d] joined\n", n);
     }
 }
-    printf("parallel end\n");
+
+init {
+    printf("program start\n");
+    // array initialization
+    {
+        int i;
+        for (i in a) {
+            int value;
+            select(value: 0 .. R);
+            a[i] = value;
+            printf("a[%d]: %d\n", i, value);
+        }
+    }
+
+    printf("sequential start\n");
+    run SequentialReverser();
+
+    printf("parallel start\n");
+    run ParallelReverser();
+
+    (done[0] == true && done[N] == true);
 
     // test if seq and parallel are the same
     {
         int i;
         for (i: 0 .. (LENGTH - 1)) {
             if
-            :: (reversed_seq[i] != reversed_par[i]) -> seq_eq_to_parallel = false;
+            :: (r_s[i] != r_p[i]) -> seq_eq_to_parallel = false;
             fi
         }
     }
@@ -112,7 +116,7 @@ ltl termination {
 // ifelse(LTL, correctness_seq, `
 ltl correctness_seq {
     [] (done[0] == true -> (true for(`k', 0, LENGTH-1, ` &&
-        reversed_seq[eval(LENGTH - k - 1)] == to_reverse[k]')))
+        r_s[eval(LENGTH - k - 1)] == a[k]')))
 }
 // ', `')
 
@@ -120,6 +124,6 @@ ltl correctness_seq {
 // ifelse(LTL, correctness_par, `
 ltl correctness_par {
     [] (done[2] == true -> (true for(`k', 0, LENGTH / N - 1, ` &&
-        reversed_par[eval(LENGTH - k - 1)] == to_reverse[k]')))
+        r_p[eval(LENGTH - k - 1)] == a[k]')))
 }
 // ', `')

ReversalModel/reversal_seq_eq_parallel_2_3_2.pml

@@ -0,0 +1,118 @@
+/* 
+m4 for loop definition
+
+
+*/
+
+int a[3]; // array to reverse
+int r_s[3]; // for SequentialReverser: where the reverse is stored 
+int r_p[3]; // for ParallelReverser: where the reverse is stored
+
+// stores termination of each reverser
+// index 0 is for the sequential algorithm
+// indices 1-2 are for the ThreadedReverser instances
+bool done[2 + 1]; // initialized to false
+
+bool seq_eq_to_parallel = true;
+
+// ThreadedReverser implementation
+proctype ThreadedReverser(int from; int to; int n) {
+    printf("proc[%d]: started from=%d to=%d\n", n, from, to);
+
+    int k;
+    for (k: from .. (to - 1)) {
+        printf("r_p[%d] = a[%d]\n", 3 - k - 1, k);
+        r_p[3 - k - 1] = a[k];
+    }
+
+    printf("proc[%d]: ended\n", n);
+    done[n] = true;
+}
+
+// SequentialReverser implementation
+proctype SequentialReverser() {
+    int k;
+    for (k: 0 .. (3 - 1)) {
+        r_s[3 - k - 1] = a[k];
+        printf("r_s[%d] = a[%d]\n", 3 - k - 1, k);
+    }
+    done[0] = true; // mark sequential end
+}
+
+// ParallelReverser implementation
+proctype ParallelReverser() {
+    int n;
+    int s = 3 / 2;
+    
+    // fork section
+    for (n: 0 .. (2 - 1)) {
+        int from = n * s;
+        int to;
+        if
+        :: (n == 2 - 1) -> to = 3;
+        :: else -> to = n * s + s; 
+        fi
+        run ThreadedReverser(from, to, n + 1); // run as "thread n"
+    }
+
+    // join section
+    for (n: 1 .. 2) {
+        (done[n] == true); // wait "thread n"
+        printf("[%d] joined\n", n);
+    }
+}
+
+init {
+    printf("program start\n");
+    // array initialization
+    {
+        int i;
+        for (i in a) {
+            int value;
+            select(value: 0 .. 2);
+            a[i] = value;
+            printf("a[%d]: %d\n", i, value);
+        }
+    }
+
+    printf("sequential start\n");
+    run SequentialReverser();
+
+    printf("parallel start\n");
+    run ParallelReverser();
+
+    (done[0] == true && done[2] == true);
+
+    // test if seq and parallel are the same
+    {
+        int i;
+        for (i: 0 .. (3 - 1)) {
+            if
+            :: (r_s[i] != r_p[i]) -> seq_eq_to_parallel = false;
+            fi
+        }
+    }
+}
+
+// ltl syntax: https://spinroot.com/spin/Man/ltl.html
+
+ltl seq_eq_parallel {
+    // the variable seq_eq_to_parallel will never be false if all the elements
+    // between the sequential and parallel reversed arrays are equal
+    [] (seq_eq_to_parallel == true)
+}
+
+ltl termination {
+    // termination happens when the sequential reverser terminates
+    // (done[0] is true) and the last process in the parallel reverser joins
+    // (done[2] is true)
+    <> (done[0] == true && done[2] == true)
+}
+
+// Due to avoid excessive parser complexity when checking the model
+// with other ltl properties the correctness_seq is excluded by m4 from the 
+// ProMeLa source when there is no need to check it
+// 
+
+// Similar exclusion logic is applied to correctness_par
+// 

ReversalModel/run.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -e
+
+SCRIPT_DIR=$(cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd)
+
+cc="gcc-13"
+
+if [ "$#" -ne 54]; then
+    echo "$0: [ltl-prop] [n] [length] [r]" > /dev/stderr
+    exit 1
+fi
+
+id="${1}_${2}_${3}_${4}"
+filename="reversal_$id.pml"
+pan_name="pan_$id"
+
+compile_dir="$(mktemp -d)"
+cp "$SCRIPT_DIR/reversal.pml.m4" "$compile_dir"
+cd "$compile_dir"
+
+m4 -DN="$2" -DLENGTH="$3" -DR="$4" -DLTL="$1" reversal.pml.m4 > "$filename"
+spin -a "$filename"
+"$cc" -Wno-format-overflow -o "$pan_name" pan.c
+
+"./$pan_name" -a -N "$1" 
+
+cd "$SCRIPT_DIR"
+rm -rf "$compile_dir"

report.tex

@@ -271,6 +271,19 @@ it is declared and set to a meaningful value in this block of the model.
 
 \subsection{LTL properties}
 
+In this section I cover the LTL property definitions I included in the model.
+
+The following LTL property definition checks that once both reversers have
+terminated, the content of  
+
+\begin{minted}{c}
+ltl seq_eq_parallel {
+    [] (seq_eq_to_parallel == true)
+}
+\end{minted}
+
+
+
 
         The citation \cite{tange_2023_7855617}.
 The citation \cite{spin}.