diff --git a/swh/provenance/revisited.gr.py b/swh/provenance/revisited.gr.py
new file mode 100644
index 0000000..acbe35d
--- /dev/null
+++ b/swh/provenance/revisited.gr.py
@@ -0,0 +1,106 @@
+def revision_process_content(
+    provenance: ProvenanceInterface,
+    revision: RevisionEntry,
+    directory: DirectoryEntry
+):
+    stack = [(directory, directory.name)]
+
+    while stack:
+        # Get next directory to process and query its date right before
+        # processing to be sure we get the most recently updated value.
+        current, path = stack.pop()
+        date = provenance.directory_get_date_in_isochrone_frontier(current)
+
+        if date is None:
+            # The directory has never been seen on the isochrone graph of a
+            # revision. Its children should be checked.
+            blobs = [child for child in iter(current) if isinstance(child, FileEntry)]
+            dirs = [child for child in iter(current) if isinstance(child, DirectoryEntry)]
+
+            blobdates = provenance.content_get_early_dates(blobs)
+            dirdates = provenance.directory_get_early_dates(dirs)
+
+            # Get the list of ids with no duplicates to ensure we have
+            # available dates for all the elements. This prevents takign a
+            # wrong decision when a blob occurres more than once in the same
+            # directory.
+            ids = list(dict.fromkeys([child.id for child in blobs + dirs]))
+            if ids:
+                dates = list(blobdates.values()) + list(dirdates.values())
+
+                if len(dates) == len(ids):
+                    # All child nodes of current directory are already known.
+                    maxdate = max(dates) < revision.date
+                    # GR : ok all childs have a known date
+
+                    if maxdate < revision.date:
+                        # The directory belongs to the isochrone frontier of the
+                        # current revision, and this is the first time it appears
+                        # as such.
+                        # FIXME GR : GR do not agree.
+                        #          : it means that this directory is outside the isochrone frontier
+                        #          : but may be not at the frontier if its parent directory is such that maxdate<revision.date
+                        #          : That's why directory of the outer isochrone frontier must be filled when 
+                        #         : their parent directory in the inner isochrone frontier are processed. 
+                        provenance.directory_set_date_in_isochrone_frontier(current, maxdate)
+                        provenance.directory_add_to_revision(revision, current, path)
+                        directory_process_content(
+                            provenance,
+                            directory=current,
+                            relative=current,
+                            prefix=PosixPath('.')
+                        )
+
+                    elif revision.date < maxdate:
+                        # This revision is out of order. All the children from
+                        # the current directory should be updated yet current
+                        # directory does not belong to the isochrone frontier.
+                        # FIXME GR 2  :  I think that in this case it is more than updating content timestamp.
+                        #               it can lead to new directory node
+                        directory_update_content(
+                            stack, provenance, revision, current, path,
+                            subdirs=dirs, blobs=blobs, blobdates=blobdates)
+
+
+                    else:
+                        # Directory is in the inner frontier and its children
+                        # have already been analyzed. Nothing to do.
+                        # FIXME: Although we are not updating timestamps here,
+                        # I guess we still need to walk the diretory to
+                        # fill the content_early_in_revision table, doesn't we?
+                        # FIXME GR 3 : yes (see provenance.gr.py and FIXME 1 above)
+                        # Otherwise will be missing some blob occurrences.
+                        # If so, we should marge this branch with the previous
+                        # one.
+                        pass
+
+                else:
+                    # Al least one child node is known, ie. the directory is
+                    # FIXME GR 4 : do you mean unkown ? 
+                    #            : if content child nodes are unkown it does matter, 
+                    #            : you can process them since they will be added to 
+                    #            : the content-revision table, but if a directory 
+                    #            : is unkown you have to process them.
+                    # not on the isochrone frontier of the current revision.
+                    # Its child nodes should be analyzed and current directory
+                    # updated before them.
+                    # FIXME: I believe the only different between this branche
+                    # and the tow 'else' cases above is this push to the stack.
+                    # If so, we might refactor this to avoid so many branches.
+                    stack.append((current, path))
+                    directory_update_content(
+                        stack, provenance, revision, current, path,
+                        subdirs=dirs, blobs=blobs, blobdates=blobdates)
+
+        elif revision.date < date:
+            # The directory has already been seen on the isochrone frontier of
+            # a revision, but current revision is earlier. Its children should
+            # be updated.
+            directory_update_content(stack, provenance, revision, current, path)
+            provenance.directory_set_date_in_isochrone_frontier(current, revision.date)
+
+        else:
+            # The directory has already been seen on the isochrone frontier of
+            # an earlier revision. Just add it to the current revision.
+            provenance.directory_add_to_revision(revision, current, path)
+
diff --git a/swh/provenance/revisited.py b/swh/provenance/revisited.py
new file mode 100644
index 0000000..ff4ba7e
--- /dev/null
+++ b/swh/provenance/revisited.py
@@ -0,0 +1,91 @@
+def revision_process_content(
+    provenance: ProvenanceInterface,
+    revision: RevisionEntry,
+    directory: DirectoryEntry
+):
+    stack = [(directory, directory.name)]
+
+    while stack:
+        # Get next directory to process and query its date right before
+        # processing to be sure we get the most recently updated value.
+        current, path = stack.pop()
+        date = provenance.directory_get_date_in_isochrone_frontier(current)
+
+        if date is None:
+            # The directory has never been seen on the isochrone graph of a
+            # revision. Its children should be checked.
+            blobs = [child for child in iter(current) if isinstance(child, FileEntry)]
+            dirs = [child for child in iter(current) if isinstance(child, DirectoryEntry)]
+
+            blobdates = provenance.content_get_early_dates(blobs)
+            dirdates = provenance.directory_get_early_dates(dirs)
+
+            # Get the list of ids with no duplicates to ensure we have
+            # available dates for all the elements. This prevents takign a
+            # wrong decision when a blob occurres more than once in the same
+            # directory.
+            ids = list(dict.fromkeys([child.id for child in blobs + dirs]))
+            if ids:
+                dates = list(blobdates.values()) + list(dirdates.values())
+
+                if len(dates) == len(ids):
+                    # All child nodes of current directory are already known.
+                    maxdate = max(dates) < revision.date
+
+                    if maxdate < revision.date:
+                        # The directory belongs to the isochrone frontier of the
+                        # current revision, and this is the first time it appears
+                        # as such.
+                        provenance.directory_set_date_in_isochrone_frontier(current, maxdate)
+                        provenance.directory_add_to_revision(revision, current, path)
+                        directory_process_content(
+                            provenance,
+                            directory=current,
+                            relative=current,
+                            prefix=PosixPath('.')
+                        )
+
+                    elif revision.date < maxdate:
+                        # This revision is out of order. All the children from
+                        # the current directory should be updated yet current
+                        # directory does not belong to the isochrone frontier.
+                        directory_update_content(
+                            stack, provenance, revision, current, path,
+                            subdirs=dirs, blobs=blobs, blobdates=blobdates)
+
+                    else:
+                        # Directory is in the inner frontier and its children
+                        # have already been analyzed. Nothing to do.
+                        # FIXME: Although we are not updating timestamps here,
+                        # I guess we still need to walk the diretory to
+                        # fill the content_early_in_revision table, doesn't we?
+                        # Otherwise will be missing some blob occurrences.
+                        # If so, we should marge this branch with the previous
+                        # one.
+                        pass
+
+                else:
+                    # Al least one child node is known, ie. the directory is
+                    # not on the isochrone frontier of the current revision.
+                    # Its child nodes should be analyzed and current directory
+                    # updated before them.
+                    # FIXME: I believe the only different between this branche
+                    # and the tow 'else' cases above is this push to the stack.
+                    # If so, we might refactor this to avoid so many branches.
+                    stack.append((current, path))
+                    directory_update_content(
+                        stack, provenance, revision, current, path,
+                        subdirs=dirs, blobs=blobs, blobdates=blobdates)
+
+        elif revision.date < date:
+            # The directory has already been seen on the isochrone frontier of
+            # a revision, but current revision is earlier. Its children should
+            # be updated.
+            directory_update_content(stack, provenance, revision, current, path)
+            provenance.directory_set_date_in_isochrone_frontier(current, revision.date)
+
+        else:
+            # The directory has already been seen on the isochrone frontier of
+            # an earlier revision. Just add it to the current revision.
+            provenance.directory_add_to_revision(revision, current, path)
+