diff --git a/libisofs/branches/thomas/libisofs/filter.c b/libisofs/branches/thomas/libisofs/filter.c
new file mode 100644
index 00000000..a7f2be69
--- /dev/null
+++ b/libisofs/branches/thomas/libisofs/filter.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2008 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+#include "libisofs.h"
+#include "filter.h"
+#include "node.h"
+
+
+void iso_filter_ref(FilterContext *filter)
+{
+    ++filter->refcount;
+}
+
+void iso_filter_unref(FilterContext *filter)
+{
+    if (--filter->refcount == 0) {
+        filter->free(filter);
+        free(filter);
+    }
+}
+
+int iso_file_add_filter(IsoFile *file, FilterContext *filter, int flag)
+{
+    int ret;
+    IsoStream *original, *filtered;
+    if (file == NULL || filter == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    
+    original = file->stream;
+
+    if (!iso_stream_is_repeatable(original)) {
+        /* TODO use custom error */
+        return ISO_WRONG_ARG_VALUE;
+    }
+    
+    ret = filter->get_filter(filter, original, &filtered);
+    if (ret < 0) {
+        return ret;
+    }
+    iso_stream_unref(original);
+    file->stream = filtered;
+    return ISO_SUCCESS;
+}
diff --git a/libisofs/branches/thomas/libisofs/filter.h b/libisofs/branches/thomas/libisofs/filter.h
new file mode 100644
index 00000000..f711fe31
--- /dev/null
+++ b/libisofs/branches/thomas/libisofs/filter.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2008 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+#ifndef LIBISO_FILTER_H_
+#define LIBISO_FILTER_H_
+
+/*
+ * Definitions of filters.
+ */
+
+/* dev_id for stream identification */
+#define XOR_ENCRYPT_DEV_ID      1
+
+typedef struct filter_context FilterContext;
+
+struct filter_context {
+    int version; /* reserved for future usage, set to 0 */
+    int refcount; 
+    
+    /** filter specific shared data */
+    void *data;
+
+    /** 
+     * Factory method to create a filtered stream from another stream.
+     * 
+     * @param original
+     *      The original stream to be filtered. If the filter needs a ref to
+     *      it (most cases), it should take a ref to it with iso_stream_ref().
+     * @param filtered
+     *      Will be filled with the filtered IsoStream (reference belongs to 
+     *      caller).
+     * @return
+     *      1 on success, < 0 on error
+     */
+    int (*get_filter)(FilterContext *filter, IsoStream *original, 
+                      IsoStream **filtered);
+
+    /**
+     * Free implementation specific data. Should never be called by user.
+     * Use iso_filter_unref() instead.
+     */
+    void (*free)(FilterContext *filter);
+};
+
+/**
+ * 
+ * @param flag
+ *      Reserved for future usage, pass always 0 for now. 
+ *      TODO in a future a different value can mean filter caching, where
+ *      the filter is applied once and the filtered file is stored in a temp
+ *      dir. This prevent filter to be applied several times.
+ */
+int iso_file_add_filter(IsoFile *file, FilterContext *filter, int flag);
+
+void iso_filter_ref(FilterContext *filter);
+void iso_filter_unref(FilterContext *filter);
+
+#endif /*LIBISO_FILTER_H_*/
diff --git a/libisofs/branches/thomas/libisofs/filters/xor_encrypt.c b/libisofs/branches/thomas/libisofs/filters/xor_encrypt.c
new file mode 100644
index 00000000..be83f725
--- /dev/null
+++ b/libisofs/branches/thomas/libisofs/filters/xor_encrypt.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2008 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+#include "../libisofs.h"
+#include "../filter.h"
+#include "../fsource.h"
+
+/*
+ * A simple Filter implementation for example purposes. It encrypts a file
+ * by XORing each byte by a given key.
+ */
+
+static ino_t xor_ino_id = 0;
+
+typedef struct
+{
+    IsoStream *orig;
+    uint8_t key;
+    ino_t id;
+} XorEncryptStreamData;
+
+static
+int xor_encrypt_stream_open(IsoStream *stream)
+{
+    XorEncryptStreamData *data;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = (XorEncryptStreamData*)stream->data;
+    return iso_stream_open(data->orig);
+}
+
+static
+int xor_encrypt_stream_close(IsoStream *stream)
+{
+    XorEncryptStreamData *data;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = stream->data;
+    return iso_stream_close(data->orig);
+}
+
+static
+off_t xor_encrypt_stream_get_size(IsoStream *stream)
+{
+    XorEncryptStreamData *data;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = stream->data;
+    return iso_stream_get_size(data->orig);
+}
+
+static
+int xor_encrypt_stream_read(IsoStream *stream, void *buf, size_t count)
+{
+    int ret, len;
+    XorEncryptStreamData *data;
+    uint8_t *buffer = buf;
+
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = stream->data;
+    ret = iso_stream_read(data->orig, buf, count);
+    if (ret < 0) {
+        return ret;
+    }
+    
+    /* xor */
+    for (len = 0; len < ret; ++len) {
+        buffer[len] = buffer[len] ^ data->key;
+    }
+    
+    return ret;
+}
+
+static
+int xor_encrypt_stream_is_repeatable(IsoStream *stream)
+{
+    /* the filter can't be created if underlying stream is not repeatable */
+    return 1;
+}
+
+static
+void xor_encrypt_stream_get_id(IsoStream *stream, unsigned int *fs_id, 
+                               dev_t *dev_id, ino_t *ino_id)
+{
+    XorEncryptStreamData *data = stream->data;
+    *fs_id = ISO_FILTER_FS_ID;
+    *dev_id = XOR_ENCRYPT_DEV_ID;
+    *ino_id = data->id;
+}
+
+static
+void xor_encrypt_stream_free(IsoStream *stream)
+{
+    XorEncryptStreamData *data = stream->data;
+    iso_stream_unref(data->orig);
+    free(data);
+}
+
+IsoStreamIface xor_encrypt_stream_class = {
+    0,
+    "xorf",
+    xor_encrypt_stream_open,
+    xor_encrypt_stream_close,
+    xor_encrypt_stream_get_size,
+    xor_encrypt_stream_read,
+    xor_encrypt_stream_is_repeatable,
+    xor_encrypt_stream_get_id,
+    xor_encrypt_stream_free
+};
+
+
+static
+void xor_encrypt_filter_free(FilterContext *filter)
+{
+    free(filter->data);
+}
+
+static
+int xor_encrypt_filter_get_filter(FilterContext *filter, IsoStream *original, 
+                  IsoStream **filtered)
+{
+    IsoStream *str;
+    XorEncryptStreamData *data;
+
+    if (filter == NULL || original == NULL || filtered == NULL) {
+        return ISO_NULL_POINTER;
+    }
+
+    str = malloc(sizeof(IsoStream));
+    if (str == NULL) {
+        return ISO_OUT_OF_MEM;
+    }
+    data = malloc(sizeof(XorEncryptStreamData));
+    if (str == NULL) {
+        free(str);
+        return ISO_OUT_OF_MEM;
+    }
+
+    /* fill data */
+    data->key = *((uint8_t*)filter->data);
+    data->id = xor_ino_id++;
+
+    /* get reference to the source */
+    data->orig = original;
+    iso_stream_ref(original);
+    
+    str->refcount = 1;
+    str->data = data;
+    str->class = &xor_encrypt_stream_class;
+
+    *filtered = str;
+    return ISO_SUCCESS;
+}
+
+int create_xor_encrypt_filter(uint8_t key, FilterContext **filter)
+{
+    FilterContext *f;
+    uint8_t *data;
+    
+    f = calloc(1, sizeof(FilterContext));
+    if (f == NULL) {
+        return ISO_OUT_OF_MEM;
+    }
+    data = malloc(sizeof(uint8_t));
+    if (data == NULL) {
+        free(f);
+        return ISO_OUT_OF_MEM;
+    }
+    f->refcount = 1;
+    f->version = 0;
+    *data = key;
+    f->data = data;
+    f->free = xor_encrypt_filter_free;
+    f->get_filter = xor_encrypt_filter_get_filter;
+    
+    return ISO_SUCCESS;
+}
diff --git a/libisofs/branches/thomas/libisofs/find.c b/libisofs/branches/thomas/libisofs/find.c
new file mode 100644
index 00000000..02881130
--- /dev/null
+++ b/libisofs/branches/thomas/libisofs/find.c
@@ -0,0 +1,617 @@
+/*
+ * Copyright (c) 2008 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+#include "libisofs.h"
+#include "node.h"
+
+#include <fnmatch.h>
+#include <string.h>
+
+struct iso_find_condition
+{
+    /*
+     * Check whether the given node matches this condition.
+     * 
+     * @param cond
+     *      The condition to check
+     * @param node
+     *      The node that should be checked
+     * @return
+     *      1 if the node matches the condition, 0 if not
+     */
+    int (*matches)(IsoFindCondition *cond, IsoNode *node);
+    
+    /**
+     * Free condition specific data
+     */
+    void (*free)(IsoFindCondition*);
+    
+    /** condition specific data */
+    void *data;
+};
+
+struct find_iter_data
+{
+    IsoDirIter *iter;
+    IsoFindCondition *cond;
+};
+
+static
+int find_iter_next(IsoDirIter *iter, IsoNode **node)
+{
+    int ret;
+    IsoNode *n;
+    struct find_iter_data *data = iter->data;
+    
+    while ((ret = iso_dir_iter_next(data->iter, &n)) == 1) {
+        if (data->cond->matches(data->cond, n)) {
+            *node = n;
+            break;
+        }
+    }
+    return ret;
+}
+
+static
+int find_iter_has_next(IsoDirIter *iter)
+{
+    struct find_iter_data *data = iter->data;
+    
+    /*
+     * FIXME wrong implementation!!!! the underlying iter may have more nodes,
+     * but they may not match find conditions
+     */
+    return iso_dir_iter_has_next(data->iter);
+}
+
+static
+void find_iter_free(IsoDirIter *iter)
+{
+    struct find_iter_data *data = iter->data;
+    data->cond->free(data->cond);
+    free(data->cond);
+    iso_dir_iter_free(data->iter);
+    free(iter->data);
+}
+
+static
+int find_iter_take(IsoDirIter *iter)
+{
+    struct find_iter_data *data = iter->data;
+    return iso_dir_iter_take(data->iter);
+}
+
+static
+int find_iter_remove(IsoDirIter *iter)
+{
+    struct find_iter_data *data = iter->data;
+    return iso_dir_iter_remove(data->iter);
+}
+
+static
+struct iso_dir_iter_iface find_iter_class = {
+        find_iter_next,
+        find_iter_has_next,
+        find_iter_free,
+        find_iter_take,
+        find_iter_remove
+};
+
+int iso_dir_find_children(IsoDir* dir, IsoFindCondition *cond, 
+                          IsoDirIter **iter)
+{
+    int ret;
+    IsoDirIter *children;
+    IsoDirIter *it;
+    struct find_iter_data *data;
+
+    if (dir == NULL || cond == NULL || iter == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    it = malloc(sizeof(IsoDirIter));
+    if (it == NULL) {
+        return ISO_OUT_OF_MEM;
+    }
+    data = malloc(sizeof(struct find_iter_data));
+    if (data == NULL) {
+        free(it);
+        return ISO_OUT_OF_MEM;
+    }
+    ret = iso_dir_get_children(dir, &children);
+    if (ret < 0) {
+        free(it);
+        free(data);
+        return ret;
+    }
+
+    it->class = &find_iter_class;
+    it->dir = (IsoDir*)dir;
+    data->iter = children;
+    data->cond = cond;
+    it->data = data;
+
+    *iter = it;
+    return ISO_SUCCESS;
+}
+
+/*************** find by name wildcard condition *****************/
+
+static
+int cond_name_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    char *pattern = (char*) cond->data;
+    int ret = fnmatch(pattern, node->name, 0);
+    return ret == 0 ? 1 : 0;
+}
+
+static
+void cond_name_free(IsoFindCondition *cond)
+{
+    free(cond->data);
+}
+
+/**
+ * Create a new condition that checks if the node name matches the given
+ * wildcard.
+ * 
+ * @param wildcard
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_name(const char *wildcard)
+{
+    IsoFindCondition *cond;
+    if (wildcard == NULL) {
+        return NULL;
+    }
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    cond->data = strdup(wildcard);
+    cond->free = cond_name_free;
+    cond->matches = cond_name_matches;
+    return cond;
+}
+
+/*************** find by mode condition *****************/
+
+static
+int cond_mode_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    mode_t *mask = (mode_t*) cond->data;
+    return node->mode & *mask ? 1 : 0;
+}
+
+static
+void cond_mode_free(IsoFindCondition *cond)
+{
+    free(cond->data);
+}
+
+/**
+ * Create a new condition that checks the node mode against a mode mask. It
+ * can be used to check both file type and permissions.
+ * 
+ * For example:
+ * 
+ * iso_new_find_conditions_mode(S_IFREG) : search for regular files
+ * iso_new_find_conditions_mode(S_IFCHR | S_IWUSR) : search for character 
+ *     devices where owner has write permissions.
+ * 
+ * @param mask
+ *      Mode mask to AND against node mode.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_mode(mode_t mask)
+{
+    IsoFindCondition *cond;
+    mode_t *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(mode_t));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    *data = mask;
+    cond->data = data;
+    cond->free = cond_mode_free;
+    cond->matches = cond_mode_matches;
+    return cond;
+}
+
+/*************** find by gid condition *****************/
+
+static
+int cond_gid_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    gid_t *gid = (gid_t*) cond->data;
+    return node->gid == *gid ? 1 : 0;
+}
+
+static
+void cond_gid_free(IsoFindCondition *cond)
+{
+    free(cond->data);
+}
+
+/**
+ * Create a new condition that checks the node gid.
+ * 
+ * @param gid
+ *      Desired Group Id.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_gid(gid_t gid)
+{
+    IsoFindCondition *cond;
+    gid_t *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(gid_t));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    *data = gid;
+    cond->data = data;
+    cond->free = cond_gid_free;
+    cond->matches = cond_gid_matches;
+    return cond;
+}
+
+/*************** find by uid condition *****************/
+
+static
+int cond_uid_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    uid_t *uid = (uid_t*) cond->data;
+    return node->uid == *uid ? 1 : 0;
+}
+
+static
+void cond_uid_free(IsoFindCondition *cond)
+{
+    free(cond->data);
+}
+
+/**
+ * Create a new condition that checks the node uid.
+ * 
+ * @param uid
+ *      Desired User Id.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_uid(uid_t uid)
+{
+    IsoFindCondition *cond;
+    uid_t *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(uid_t));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    *data = uid;
+    cond->data = data;
+    cond->free = cond_uid_free;
+    cond->matches = cond_uid_matches;
+    return cond;
+}
+
+/*************** find by timestamps condition *****************/
+
+struct cond_times
+{
+    time_t time;
+    int what_time; /* 0 atime, 1 mtime, 2 ctime */
+    enum iso_find_comparisons comparison;
+};
+
+static
+int cond_time_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    time_t node_time;
+    struct cond_times *data = cond->data;
+    
+    switch (data->what_time) {
+    case 0: node_time = node->atime; break;
+    case 1: node_time = node->mtime; break;
+    default: node_time = node->ctime; break;
+    }
+    
+    switch (data->comparison) {
+    case ISO_FIND_COND_GREATER:
+        return node_time > data->time ? 1 : 0;
+    case ISO_FIND_COND_GREATER_OR_EQUAL:
+        return node_time >= data->time ? 1 : 0;
+    case ISO_FIND_COND_EQUAL:
+        return node_time == data->time ? 1 : 0;
+    case ISO_FIND_COND_LESS:
+        return node_time < data->time ? 1 : 0;
+    case ISO_FIND_COND_LESS_OR_EQUAL:
+        return node_time <= data->time ? 1 : 0;
+    }
+    /* should never happen */
+    return 0;
+}
+
+static
+void cond_time_free(IsoFindCondition *cond)
+{
+    free(cond->data);
+}
+
+/**
+ * Create a new condition that checks the time of last access.
+ * 
+ * @param time
+ *      Time to compare against IsoNode atime.
+ * @param comparison
+ *      Comparison to be done between IsoNode atime and submitted time.
+ *      Note that ISO_FIND_COND_GREATER, for example, is true if the node
+ *      time is greater than the submitted time.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_atime(time_t time, 
+                      enum iso_find_comparisons comparison)
+{
+    IsoFindCondition *cond;
+    struct cond_times *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(struct cond_times));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    data->time = time;
+    data->comparison = comparison;
+    data->what_time = 0; /* atime */
+    cond->data = data;
+    cond->free = cond_time_free;
+    cond->matches = cond_time_matches;
+    return cond;
+}
+
+/**
+ * Create a new condition that checks the time of last modification.
+ * 
+ * @param time
+ *      Time to compare against IsoNode mtime.
+ * @param comparison
+ *      Comparison to be done between IsoNode mtime and submitted time.
+ *      Note that ISO_FIND_COND_GREATER, for example, is true if the node
+ *      time is greater than the submitted time.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_mtime(time_t time, 
+                      enum iso_find_comparisons comparison)
+{
+    IsoFindCondition *cond;
+    struct cond_times *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(struct cond_times));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    data->time = time;
+    data->comparison = comparison;
+    data->what_time = 1; /* mtime */
+    cond->data = data;
+    cond->free = cond_time_free;
+    cond->matches = cond_time_matches;
+    return cond;
+}
+
+/**
+ * Create a new condition that checks the time of last status change.
+ * 
+ * @param time
+ *      Time to compare against IsoNode ctime.
+ * @param comparison
+ *      Comparison to be done between IsoNode ctime and submitted time.
+ *      Note that ISO_FIND_COND_GREATER, for example, is true if the node
+ *      time is greater than the submitted time.
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_ctime(time_t time, 
+                      enum iso_find_comparisons comparison)
+{
+    IsoFindCondition *cond;
+    struct cond_times *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(struct cond_times));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    data->time = time;
+    data->comparison = comparison;
+    data->what_time = 2; /* ctime */
+    cond->data = data;
+    cond->free = cond_time_free;
+    cond->matches = cond_time_matches;
+    return cond;
+}
+
+/*************** logical operations on conditions *****************/
+
+struct logical_binary_conditions {
+    IsoFindCondition *a;
+    IsoFindCondition *b;
+};
+
+static
+void cond_logical_binary_free(IsoFindCondition *cond)
+{
+    struct logical_binary_conditions *data;
+    data = cond->data;
+    data->a->free(data->a);
+    free(data->a);
+    data->b->free(data->b);
+    free(data->b);
+    free(cond->data);
+}
+
+static
+int cond_logical_and_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    struct logical_binary_conditions *data = cond->data;
+    return data->a->matches(data->a, node) && data->b->matches(data->b, node);
+}
+
+/**
+ * Create a new condition that check if the two given conditions are
+ * valid.
+ * 
+ * @param a
+ * @param b
+ *      IsoFindCondition to compare
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_and(IsoFindCondition *a, 
+                                              IsoFindCondition *b)
+{
+    IsoFindCondition *cond;
+    struct logical_binary_conditions *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(struct logical_binary_conditions));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    data->a = a;
+    data->b = b;
+    cond->data = data;
+    cond->free = cond_logical_binary_free;
+    cond->matches = cond_logical_and_matches;
+    return cond;
+}
+
+static
+int cond_logical_or_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    struct logical_binary_conditions *data = cond->data;
+    return data->a->matches(data->a, node) || data->b->matches(data->b, node);
+}
+
+/**
+ * Create a new condition that check if at least one the two given conditions 
+ * is valid.
+ * 
+ * @param a
+ * @param b
+ *      IsoFindCondition to compare
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_or(IsoFindCondition *a, 
+                                              IsoFindCondition *b)
+{
+    IsoFindCondition *cond;
+    struct logical_binary_conditions *data;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    data = malloc(sizeof(struct logical_binary_conditions));
+    if (data == NULL) {
+        free(cond);
+        return NULL;
+    }
+    data->a = a;
+    data->b = b;
+    cond->data = data;
+    cond->free = cond_logical_binary_free;
+    cond->matches = cond_logical_or_matches;
+    return cond;
+}
+
+static
+void cond_not_free(IsoFindCondition *cond)
+{
+    IsoFindCondition *negate = cond->data;
+    negate->free(negate);
+    free(negate);
+}
+
+static
+int cond_not_matches(IsoFindCondition *cond, IsoNode *node)
+{
+    IsoFindCondition *negate = cond->data;
+    return !(negate->matches(negate, node));
+}
+
+/**
+ * Create a new condition that check if the given conditions is false.
+ * 
+ * @param negate
+ * @result
+ *      The created IsoFindCondition, NULL on error.
+ * 
+ * @since 0.6.4
+ */
+IsoFindCondition *iso_new_find_conditions_not(IsoFindCondition *negate)
+{
+    IsoFindCondition *cond;
+    cond = malloc(sizeof(IsoFindCondition));
+    if (cond == NULL) {
+        return NULL;
+    }
+    cond->data = negate;
+    cond->free = cond_not_free;
+    cond->matches = cond_not_matches;
+    return cond;
+}
+