.. index:: single: unweighted_directed_graph(Dictionary) .. _unweighted_directed_graph/1:

.. rst-class:: right

object

unweighted_directed_graph(Dictionary)

Unweighted directed graph predicates using a dictionary representation. The parametric object parameter is the dictionary to use for the graph representation.

| Availability: | logtalk_load(graphs(loader))

| Author: Paulo Moura | Version: 1:0:0 | Date: 2026-02-20

| Compilation flags: | static, context_switching_calls

| Imports: | public :ref:`unweighted_graph_common(Dictionary) <unweighted_graph_common/1>` | public :ref:`directed_graph_common <directed_graph_common/0>` | Uses: | :ref:`pairs <pairs/0>` | :ref:`set <set/0>`

| Remarks: | (none)

| Inherited public predicates: |  :ref:`unweighted_graph_protocol/0::add_edge/4`  :ref:`graph_protocol/0::add_edges/3`  :ref:`graph_protocol/0::add_vertex/3`  :ref:`graph_protocol/0::add_vertices/3`  :ref:`graph_protocol/0::all_pairs_min_paths/2`  :ref:`graph_protocol/0::all_pairs_min_predecessors/2`  :ref:`graph_protocol/0::breadth_first_order/3`  :ref:`unweighted_graph_protocol/0::complement/2`  :ref:`directed_graph_protocol/0::cycle/2`  :ref:`unweighted_graph_protocol/0::delete_edge/4`  :ref:`graph_protocol/0::delete_edges/3`  :ref:`graph_protocol/0::delete_vertex/3`  :ref:`graph_protocol/0::delete_vertices/3`  :ref:`graph_protocol/0::depth_first_order/3`  :ref:`unweighted_graph_protocol/0::edge/3`  :ref:`graph_protocol/0::edges/2`  :ref:`graph_protocol/0::empty/1`  :ref:`directed_graph_protocol/0::has_cycle/1`  :ref:`graph_protocol/0::has_path/3`  :ref:`directed_graph_protocol/0::in_degree/3`  :ref:`directed_graph_protocol/0::is_acyclic/1`  :ref:`graph_protocol/0::is_bipartite/1`  :ref:`graph_protocol/0::is_complete/1`  :ref:`graph_protocol/0::is_sparse/1`  :ref:`graph_protocol/0::max_path/5`  :ref:`graph_protocol/0::min_distances/3`  :ref:`graph_protocol/0::min_path/5`  :ref:`graph_protocol/0::min_predecessors/3`  :ref:`graph_protocol/0::neighbors/3`  :ref:`graph_protocol/0::new/1`  :ref:`graph_protocol/0::new/2`  :ref:`graph_protocol/0::new/3`  :ref:`graph_protocol/0::number_of_edges/2`  :ref:`graph_protocol/0::number_of_vertices/2`  :ref:`directed_graph_protocol/0::out_degree/3`  :ref:`graph_protocol/0::path/3`  :ref:`graph_protocol/0::reachable/3`  :ref:`directed_graph_protocol/0::strongly_connected_components/2`  :ref:`directed_graph_protocol/0::symmetric_closure/2`  :ref:`directed_graph_protocol/0::topological_sort/2`  :ref:`directed_graph_protocol/0::transitive_closure/2`  :ref:`directed_graph_protocol/0::transpose/2`  :ref:`graph_protocol/0::vertices/2`  :ref:`directed_graph_protocol/0::weakly_connected_components/2`  

.. contents:: :local: :backlinks: top

Public predicates

.. index:: compose/3 .. _unweighted_directed_graph/1::compose/3:

compose/3 ^^^^^^^^^^^^^

Composes NewGraph by connecting the drains of LeftGraph to the sources of RightGraph.

| Compilation flags: | static

| Template: | compose(LeftGraph,RightGraph,NewGraph) | Mode and number of proofs: | compose(+graph,+graph,-graph) - one

---

.. index:: union/3 .. _unweighted_directed_graph/1::union/3:

union/3 ^^^^^^^^^^^

Unifies UnionGraph with the union of Graph1 and Graph2.

| Compilation flags: | static

| Template: | union(Graph1,Graph2,UnionGraph) | Mode and number of proofs: | union(+graph,+graph,-graph) - one

---

.. index:: topological_sort/3 .. _unweighted_directed_graph/1::topological_sort/3:

topological_sort/3 ^^^^^^^^^^^^^^^^^^^^^^

Difference list version of topological_sort/2 where Sorted0 is the tail of Sorted.

| Compilation flags: | static

| Template: | topological_sort(Graph,Sorted0,Sorted) | Mode and number of proofs: | topological_sort(+graph,+list(vertex),-list(vertex)) - one

---

.. index:: leaves/2 .. _unweighted_directed_graph/1::leaves/2:

leaves/2 ^^^^^^^^^^^^

Unifies Leaves with a sorted list of vertices with no outgoing edges.

| Compilation flags: | static

| Template: | leaves(Graph,Leaves) | Mode and number of proofs: | leaves(+graph,-list(vertex)) - one

---

.. index:: transitive_reduction/2 .. _unweighted_directed_graph/1::transitive_reduction/2:

transitive_reduction/2 ^^^^^^^^^^^^^^^^^^^^^^^^^^

Computes the transitive reduction of the graph. An edge Vertex1-Vertex2 is in the reduction iff it is in the graph and there is no other path of length >= 2 from Vertex1 to Vertex2.

| Compilation flags: | static

| Template: | transitive_reduction(Graph,Reduction) | Mode and number of proofs: | transitive_reduction(+graph,-graph) - one

---

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)