diff --git a/src/examples.rs b/src/examples.rs
index eccf0f2..642dbf5 100644
--- a/src/examples.rs
+++ b/src/examples.rs
@@ -1,7 +1,9 @@
 #![allow(dead_code)]
 
+use petgraph::dot::Dot;
+
 use crate::rsprocess::structure::{RSset, RSsystem};
-use crate::rsprocess::translator;
+use crate::rsprocess::{graph, translator};
 use crate::rsprocess::translator::Translator;
 use crate::rsprocess::{frequency, perpetual, statistics, transitions};
 
@@ -229,3 +231,33 @@ pub fn fast_freq() -> std::io::Result<()> {
 
     Ok(())
 }
+
+// equivalent to main_do(digraph, Arcs)
+pub fn digraph() -> std::io::Result<()> {
+    let mut translator = Translator::new();
+
+    let mut path = env::current_dir()?;
+    // file to read is inside testing/
+    path = path.join("testing/first.system");
+    let system = read_file(&mut translator, path, parser_system)?;
+
+    // the system needs to terminate to return
+    let res = match graph::digraph(system) {
+        Ok(o) => o,
+        Err(e) => {
+            println!("Error computing target: {e}");
+            return Ok(());
+        }
+    };
+
+    println!("Generated graph in dot notation:\n{:?}\n", Dot::new(&res));
+
+    let res = res.map(|_, node| format!("{}; {}",
+					translator::RSsetDisplay::from(&translator, node.get_available_entities()),
+					translator::RSprocessDisplay::from(&translator, node.get_context_process())),
+		      |_, edge| translator::RSsetDisplay::from(&translator, &edge.context));
+
+    println!("Generated graph in dot notation:\n{}", Dot::new(&res));
+
+    Ok(())
+}
diff --git a/src/main.rs b/src/main.rs
index 56c36c3..e7317c9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,7 +13,7 @@ fn main() -> std::io::Result<()> {
 
     // examples::stats()?;
 
-    examples::freq()?;
+    // examples::freq()?;
 
     // examples::hoop()?;
 
@@ -25,5 +25,7 @@ fn main() -> std::io::Result<()> {
 
     // examples::fast_freq()?;
 
+    examples::digraph()?;
+
     Ok(())
 }
diff --git a/src/rsprocess/graph.rs b/src/rsprocess/graph.rs
new file mode 100644
index 0000000..52ca3ef
--- /dev/null
+++ b/src/rsprocess/graph.rs
@@ -0,0 +1,39 @@
+#![allow(dead_code)]
+
+use petgraph::Graph;
+use std::collections::HashMap;
+use super::structure::{RSlabel, RSsystem};
+use super::support_structures::TransitionsIterator;
+
+pub fn digraph(
+    system: RSsystem
+) -> Result<Graph<RSsystem, RSlabel>, String> {
+    let mut graph: Graph<RSsystem, RSlabel> = Graph::new();
+    let node = graph.add_node(system.clone());
+
+    let mut association = HashMap::new();
+    association.insert(system.clone(), node);
+
+    let mut stack = vec![system];
+    let mut current;
+
+
+    while !stack.is_empty() {
+	// depth first
+	current = stack.pop().unwrap();
+	let current_node = *association.get(&current).unwrap();
+
+	// cycle through all next nodes
+	let tr = TransitionsIterator::from(&current)?;
+
+	for (label, next) in tr {
+	    // if not already visited
+	    let next_node = association.entry(next.clone()).or_insert_with(|| {
+		stack.push(next.clone());
+		graph.add_node(next)
+	    });
+	    graph.add_edge(current_node, *next_node, label);
+	}
+    }
+    Ok(graph)
+}
diff --git a/src/rsprocess/mod.rs b/src/rsprocess/mod.rs
index 0d88a94..52662b0 100644
--- a/src/rsprocess/mod.rs
+++ b/src/rsprocess/mod.rs
@@ -7,3 +7,4 @@ pub mod structure;
 pub mod support_structures;
 pub mod transitions;
 pub mod translator;
+pub mod graph;
diff --git a/src/rsprocess/structure.rs b/src/rsprocess/structure.rs
index dd97d35..077dde1 100644
--- a/src/rsprocess/structure.rs
+++ b/src/rsprocess/structure.rs
@@ -182,7 +182,7 @@ impl Default for RSreaction {
 // -----------------------------------------------------------------------------
 // RSprocess
 // -----------------------------------------------------------------------------
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum RSprocess {
     Nill,
     RecursiveIdentifier {
@@ -475,6 +475,24 @@ impl RSsystem {
     }
 }
 
+impl PartialEq for RSsystem {
+    // we ignore delta and reaction rules
+    fn eq(&self, other: &RSsystem) -> bool {
+        self.available_entities == other.available_entities &&
+	    self.context_process == other.context_process
+    }
+}
+
+impl Eq for RSsystem {}
+
+impl Hash for RSsystem {
+    // ignores delta and reaction rules
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.available_entities.hash(state);
+        self.context_process.hash(state);
+    }
+}
+
 impl Default for RSsystem {
     fn default() -> Self {
         RSsystem::new()
diff --git a/src/rsprocess/translator.rs b/src/rsprocess/translator.rs
index 3f86d34..16da0d2 100644
--- a/src/rsprocess/translator.rs
+++ b/src/rsprocess/translator.rs
@@ -141,7 +141,7 @@ fn print_process(
     use super::structure::RSprocess::*;
     match process {
         Nill => {
-            write!(f, "[Nill]")
+            write!(f, "Nill")
         }
         RecursiveIdentifier { identifier } => {
             write!(f,
@@ -154,7 +154,7 @@ fn print_process(
         } => {
             write!(
                 f,
-                "[entities: {}, next_process: {}]",
+                "{}.{}",
                 RSsetDisplay::from(translator, entities),
                 RSprocessDisplay::from(translator, next_process)
             )
@@ -166,7 +166,7 @@ fn print_process(
         } => {
             write!(
                 f,
-                "[repeat: {repeat}, repeated_process: {}, next_process: {}]",
+                "({})^{repeat}.{}",
                 RSprocessDisplay::from(translator, repeated_process),
                 RSprocessDisplay::from(translator, next_process)
             )
diff --git a/testing/first.system b/testing/first.system
index 3314710..aadc18c 100644
--- a/testing/first.system
+++ b/testing/first.system
@@ -1,4 +1,4 @@
-Environment: [x = {a}.y, y =({a}.nill + {b}.nill)]
+Environment: [x = {a}.y, y =({a}.x + {b}.y)]
 Initial Entities: {a, b}
 Context: [({a,b}.{a}.{a,c}.x + {a,b}.{a}.{a}.nill)]
 Reactions: ([r: {a,b}, i: {c}, p: {b}])