diff --git a/integration_tests/ruby_dsl/020_vending_machine.rb b/integration_tests/ruby_dsl/020_vending_machine.rb
new file mode 100644
index 0000000..4ad02af
--- /dev/null
+++ b/integration_tests/ruby_dsl/020_vending_machine.rb
@@ -0,0 +1,188 @@
+model :VendingMachine do
+
+  products = {
+      cola:  1.2,
+      chips: 2.5
+  }
+  products = products.map { |c, v| [c, (v * 10).to_i] }.to_h
+
+  coins = {
+      ten_cents: 10,
+      twenty_cents: 20,
+      fifty_cents: 50,
+      one_euro: 100,
+      two_euro: 200
+  }
+  coins = coins.map { |c, v| [c, (v / 10).to_i] }.to_h
+
+
+  MAX_MONEY = 100
+  START_MONEY = 20
+
+  transient error :CoinReadFails
+
+  graph :User do
+      press_states = products.keys.map { |product| :"press_#{product}" }
+      grab_states  = products.keys.map { |product| :"grab_#{product}" }
+      insert_states = coins.keys.map { |coin| :"insert_#{coin}" }
+
+      var pocket_money: (0..MAX_MONEY), init: START_MONEY
+      var value_in_products: (0..MAX_MONEY), init: 0
+
+      states :inserting, *insert_states, \
+             :pressing, *press_states, \
+             :waiting, :grab_product, \
+             :grab_change, \
+             :done, \
+             init: :inserting
+
+      # The user can insert coins until the money runs out
+      coins.each { |coin, value|
+        transition :inserting => :"insert_#{coin}" do
+          guard  "pocket_money - #{value} >= 0"
+          action "pocket_money := pocket_money - #{value}"
+        end
+        transition :"insert_#{coin}" => :inserting
+      }
+
+      # The user can decide at any point to start pressing buttons
+      transition :inserting => :pressing
+
+      # Press one button and wait for the result
+      products.each { |product, value|
+        transition :pressing => :"press_#{product}"
+        transition :"press_#{product}" => :waiting
+      }
+
+      # Grab a product and take note of the value
+      products.each { |product, value|
+        transition :waiting => :grab_product do
+          precon "value_in_products + #{value} < #{MAX_MONEY}"
+          guard  "LED == green && Dispenser == dispensed_#{product}"
+          action "value_in_products := value_in_products + #{value}"
+        end
+      }
+      transition :grab_product => :grab_change
+
+      # Grab change directly 
+      transition :waiting => :grab_change do
+        guard "LED == red"
+      end
+
+
+      # Grab the change and be done
+      transition :grab_change => :done do
+        precon "pocket_money + change <= #{MAX_MONEY}"
+        action "pocket_money := pocket_money + change"
+      end
+  end
+
+  graph :CoinReader do
+    states :reading
+
+    var read_value: (0..coins.values.max), init: 0
+
+    coins.each { |coin, value|
+      transition :reading => :reading do
+        guard  "User == insert_#{coin} && CoinReadFails == No"
+        action "read_value := #{value}"
+      end
+    }
+
+    transition :reading => :reading do
+      guard  coins.keys.map { |coin| "User != insert_#{coin}" }.join(" && ")
+      action "read_value := 0"
+    end
+
+  end
+
+  graph :Controller do
+    var budget: (0..MAX_MONEY), init: 0
+
+    dispense_states = products.keys.map { |product| :"dispense_#{product}" }
+
+    states :accepting, *dispense_states, :rejected, :done, init: :accepting
+
+    transition :accepting => :accepting do
+      precon "budget + read_value <= #{MAX_MONEY}"
+      guard "read_value > 0"
+      action "budget := budget + read_value"
+    end
+
+    products.each { |product, value|
+      transition :accepting => :"dispense_#{product}" do
+        guard  "User == press_#{product} && budget >= #{value}"
+        action "budget := budget - #{value}"
+      end
+      transition :"dispense_#{product}" => :done
+
+      transition :accepting => :rejected do
+        guard "User == press_#{product} && budget < #{value}"
+      end
+    }
+
+    transition :accepting => :accepting do
+      guard  "CoinDispenser == dispensed_change"
+      action "budget := 0"
+    end
+    transition :done => :accepting do
+      guard  "CoinDispenser == dispensed_change"
+      action "budget := 0"
+    end
+
+
+  end
+
+  graph :LED do
+    states :idle, :red, :green, init: :idle
+
+    transition :idle => :green do
+      guard "Controller == done"
+    end
+    transition :idle => :red do
+      guard "Controller == rejected"
+    end
+
+  end
+
+  graph :Dispenser do
+    dispensed_states = products.keys.map { |product| :"dispensed_#{product}" }
+    states :empty, *dispensed_states, init: :empty
+
+    # Dispense the product the Controller tells us to
+    products.each { |product, value|
+      transition :empty => :"dispensed_#{product}" do
+        guard "Controller == dispense_#{product}"
+      end
+    }
+  end
+
+  graph :CoinDispenser do
+    states :idle, :dispensed_change, init: :idle
+    var change: (0..MAX_MONEY), init: 0
+
+    # Eject the change money
+    transition :idle => :dispensed_change do
+      guard  "Controller == rejected || Controller == done"
+      action "change := budget"
+    end
+
+  end
+
+  specify "The vending machine" do
+
+    it "allows the user to buy something" => :"EF value_in_products > 0"
+    it "always completes the transaction" => :"F User == done"
+
+    products.each { |product, value|
+      assuming "the product can be bough" => :"pocket_money >= #{value}" do
+        it "allows the user to buy #{product}" => :"EF Dispenser == dispensed_#{product}"
+      end
+    }
+
+  end
+
+  hazard "The user looses money" => :"User == done && pocket_money + value_in_products < #{START_MONEY}"
+  hazard "The machine looses money" => :"User == done && pocket_money + value_in_products > #{START_MONEY}"
+
+end