diff --git a/cookbook/src/lib.rs b/cookbook/src/lib.rs
index 31e1bb2..3aab4e2 100644
--- a/cookbook/src/lib.rs
+++ b/cookbook/src/lib.rs
@@ -1,3 +1,7 @@
+mod meal;
+
+pub use self::meal::Meal;
+
 #[cfg(test)]
 mod tests {
     #[test]
diff --git a/cookbook/src/meal.rs b/cookbook/src/meal.rs
new file mode 100644
index 0000000..506f9de
--- /dev/null
+++ b/cookbook/src/meal.rs
@@ -0,0 +1,19 @@
+
+
+#[derive(Debug,Clone)]
+pub struct Meal {
+    name: String,
+    nutritional_value: i32,
+}
+
+impl Meal {
+    pub fn new(name: String, nutritional_value: i32) -> Meal {
+        Meal { name, nutritional_value }
+    }
+
+    pub fn nutritional_value(&self) -> i32 {
+        self.nutritional_value
+    }
+}
+
+
diff --git a/cookbook/src/meals.rs b/cookbook/src/meals.rs
deleted file mode 100644
index e1561d4..0000000
--- a/cookbook/src/meals.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-
-enum Meal {
-    FullMeal,
-    Composed,
-}
-
-fn retrieve_all() -> Vec<Meal> {
-    vec!()
-}
-
-
diff --git a/planner/src/bin/weekly.rs b/planner/src/bin/weekly.rs
new file mode 100644
index 0000000..3bed713
--- /dev/null
+++ b/planner/src/bin/weekly.rs
@@ -0,0 +1,47 @@
+//! The weekly menu planner
+//!
+
+use cookbook::Meal;
+use planner::solver::{Variables, Domain, solve_all};
+
+
+fn generate_weekly_menu() -> String {
+    let assignments: Variables<Meal> = [
+        ("LundiMidi".to_string(), None), ("LundiSoir".to_string(), None),
+        ("MardiMidi".to_string(), None), ("MardiSoir".to_string(), None),
+        ("MercrediMidi".to_string(), None), ("MercrediSoir".to_string(), None),
+    ].iter().cloned().collect();
+    let meals: Domain<Meal> = Domain::new(vec![
+        Meal::new("Raclette".to_string(), 800),
+        Meal::new("Soupe".to_string(), 400),
+    ]);
+    let validator = |vars: &Variables<Meal>| {
+        let mut result = true;
+        for day in ["Lundi", "Mardi", "Mercredi"].into_iter() {
+            let all_day = vars.keys().filter(|k| k.starts_with(day));
+            let mut nutri_value = 0;
+            for key in all_day {
+                nutri_value += vars.get(key)
+                    .expect("no value here !")
+                    .expect("no meal there !")
+                    .nutritional_value()
+            }
+            println!("{} -> {}", day, nutri_value);
+            if nutri_value != 1200 { result = false; };
+        }
+        println!("Validator returns {}", result);
+        result
+    };
+
+    let solutions = solve_all(assignments, &meals, validator);
+    format!("{:#?}", solutions)
+}
+
+fn main() {
+    println!("{}", generate_weekly_menu());
+}
+
+#[cfg(test)]
+mod tests {
+
+}
diff --git a/planner/src/lib.rs b/planner/src/lib.rs
index cde50e2..ce3bbca 100644
--- a/planner/src/lib.rs
+++ b/planner/src/lib.rs
@@ -1,4 +1,6 @@
-mod solver;
+extern crate cookbook;
+
+pub mod solver;
 
 #[cfg(test)]
 mod tests {
diff --git a/planner/src/rules.rs b/planner/src/rules.rs
new file mode 100644
index 0000000..b7f24eb
--- /dev/null
+++ b/planner/src/rules.rs
@@ -0,0 +1,16 @@
+//! Rules used by the `planner`
+//! A rule is a constraint on valid solutions, but also provides insights
+//! and eventually inferences to optimize the solving process.
+
+// Nutritional values
+// - Per day : according to user profile (man: 2000kcal, woman: 1800kcal)
+// - Per meal : some meals should have higher nutrional values than others
+
+// Ingredients
+// - Per week : should use most of a limited set of ingredients (excluding
+// condiments, ...)
+// - To consume : must use a small set of ingredients (leftovers)
+//
+
+// Price
+// - Per week : should restrict ingredients cost to a given amount
diff --git a/planner/src/solver.rs b/planner/src/solver.rs
index a9456e6..31422ee 100644
--- a/planner/src/solver.rs
+++ b/planner/src/solver.rs
@@ -2,7 +2,7 @@ use std::fmt;
 use std::clone::Clone;
 use std::collections::HashMap;
 
-type Variables<'a, V> = HashMap<String, Option<&'a V>>;
+pub type Variables<'a, V> = HashMap<String, Option<&'a V>>;
 
 enum Assignment<'a, V> {
     Update(String, &'a V),
@@ -11,12 +11,12 @@ enum Assignment<'a, V> {
 
 
 #[derive(Clone)]
-struct Domain<V> {
+pub struct Domain<V> {
     values: Vec<V>
 }
 
 impl<V> Domain<V> {
-    fn new(values: Vec<V>) -> Domain<V> {
+    pub fn new(values: Vec<V>) -> Domain<V> {
         Domain { values }
     }
 }
@@ -35,6 +35,7 @@ fn assign_next<'a,'b, V>(assign: &'b Variables<'a, V>, domain: &'a Domain<V>)
     where V: fmt::Debug 
 {
     // Panics on empty domain
+    // If domain values are filtered, then the branch is a dead end
     if domain.values.is_empty() { panic!("No values in domain : {:?}", domain); };
 
     // TODO: should be able to inject a choosing strategy
@@ -51,8 +52,12 @@ fn assign_next<'a,'b, V>(assign: &'b Variables<'a, V>, domain: &'a Domain<V>)
 }
 
 /// Visit all possible solutions, using a stack.
-fn solve_all<'a, V: Clone + fmt::Debug>(mut assign: Variables<'a, V>, domain: &'a Domain<V>, is_valid: fn(&Variables<'a,V>) -> bool) 
-    -> Vec<Variables<'a, V>> 
+pub fn solve_all<'a, V>(
+    mut assign: Variables<'a, V>, 
+    domain: &'a Domain<V>, 
+    is_valid: fn(&Variables<'a,V>) -> bool
+    ) -> Vec<Variables<'a, V>> 
+    where V: Clone + fmt::Debug
 {
     let mut solutions: Vec<Variables<V>> = vec![];
     let mut stack: Vec<Assignment<'a, V>> = vec![];