diff --git a/input/src/input_dsl.rs b/input/src/input_dsl.rs
index cc54282..f4cd98f 100644
--- a/input/src/input_dsl.rs
+++ b/input/src/input_dsl.rs
@@ -62,7 +62,7 @@ impl<E: Clone + Ord, C> EventMap<E, C> {
     /// Create event map from path to text file.
     pub fn load_from_path <'s> (
         &'s mut self, path: impl AsRef<Path>
-    ) -> Usually<&mut Self> where Self: DslInto<C> + DslInto<E> {
+    ) -> Usually<&'s mut Self> where Self: DslInto<C> + DslInto<E> {
         if exists(path.as_ref())? {
             let source = read_to_string(&path)?;
             let path: Arc<PathBuf> = Arc::new(path.as_ref().into());
@@ -81,7 +81,7 @@ impl<E: Clone + Ord, C> EventMap<E, C> {
     /// Load one event binding into the event map.
     pub fn load_from_source_one <'s> (
         &'s mut self, dsl: impl Dsl, path: &Option<&Arc<PathBuf>>
-    ) -> Usually<&mut Self> where Self: DslInto<C> + DslInto<E> {
+    ) -> Usually<&'s mut Self> where Self: DslInto<C> + DslInto<E> {
         if let Some(exp)  = dsl.head()?.exp()?
         && let Some(sym)  = exp.head()?.sym()?
         && let Some(tail) = exp.tail()?
@@ -117,10 +117,10 @@ impl<E: Clone + Ord, C> EventMap<E, C> {
 }
 impl<C> Binding<C> {
     pub fn from_dsl (dsl: impl Dsl) -> Usually<Self> {
-        let mut command:     Option<C>            = None;
-        let mut condition:   Option<Condition>    = None;
-        let mut description: Option<Arc<str>>     = None;
-        let mut source:      Option<Arc<PathBuf>> = None;
+        let command:     Option<C>            = None;
+        let condition:   Option<Condition>    = None;
+        let description: Option<Arc<str>>     = None;
+        let source:      Option<Arc<PathBuf>> = None;
         if let Some(command) = command {
             Ok(Self { command, condition, description, source })
         } else {
diff --git a/output/src/ops.rs b/output/src/ops.rs
index a1c3de3..f16d971 100644
--- a/output/src/ops.rs
+++ b/output/src/ops.rs
@@ -777,27 +777,15 @@ pub struct Stack<E, F> {
     callback:  F
 }
 impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Stack<E, F> {
+    pub fn north (callback: F) -> Self { Self::new(North, callback) }
+    pub fn south (callback: F) -> Self { Self::new(South, callback) }
+    pub fn east  (callback: F) -> Self { Self::new(East, callback)  }
+    pub fn west  (callback: F) -> Self { Self::new(West, callback)  }
+    pub fn above (callback: F) -> Self { Self::new(Above, callback) }
+    pub fn below (callback: F) -> Self { Self::new(Below, callback) }
     pub fn new (direction: Direction, callback: F) -> Self {
         Self { direction, callback, __: Default::default(), }
     }
-    pub fn north (callback: F) -> Self {
-        Self::new(North, callback)
-    }
-    pub fn south (callback: F) -> Self {
-        Self::new(South, callback)
-    }
-    pub fn east (callback: F) -> Self {
-        Self::new(East, callback)
-    }
-    pub fn west (callback: F) -> Self {
-        Self::new(West, callback)
-    }
-    pub fn above (callback: F) -> Self {
-        Self::new(Above, callback)
-    }
-    pub fn below (callback: F) -> Self {
-        Self::new(Below, callback)
-    }
 }
 impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for Stack<E, F> {
     fn layout (&self, to: E::Area) -> E::Area {
@@ -808,6 +796,8 @@ impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for St
         (self.callback)(&mut move |component: &dyn Render<E>|{
             let [_, _, w, h] = component.layout([x, y, w_remaining, h_remaining].into()).xywh();
             match self.direction {
+                North | West  => { todo!() },
+                Above | Below => {},
                 South => { y           = y.plus(h);
                            h_used      = h_used.plus(h);
                            h_remaining = h_remaining.minus(h);
@@ -816,16 +806,12 @@ impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for St
                            w_used      = w_used.plus(w);
                            w_remaining = w_remaining.minus(w);
                            h_used      = h_used.max(h); },
-                North | West  => { todo!() },
-                Above | Below => {},
-                _ => unreachable!(),
             }
         });
         match self.direction {
             North | West  => { todo!() },
             South | East  => { [to.x(), to.y(), w_used.into(), h_used.into()].into() },
             Above | Below => { [to.x(), to.y(), to.w(), to.h()].into() },
-            _ => unreachable!(),
         }
     }
     fn render (&self, to: &mut E) {
@@ -836,25 +822,16 @@ impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for St
         (self.callback)(&mut move |component: &dyn Render<E>|{
             let layout = component.layout([x, y, w_remaining, h_remaining].into());
             match self.direction {
-                South => {
-                    y           = y.plus(layout.h());
-                    h_remaining = h_remaining.minus(layout.h());
-                    h_used      = h_used.plus(layout.h());
-                    to.place(layout, component);
-                },
-                East => {
-                    x           = x.plus(layout.w());
-                    w_remaining = w_remaining.minus(layout.w());
-                    w_used      = w_used.plus(layout.h());
-                    to.place(layout, component);
-                },
-                Above | Below => {
-                    to.place(layout, component);
-                }
-                North | West  => {
-                    todo!()
-                },
-                _ => unreachable!()
+                Above | Below => { to.place(layout, component);  }
+                North | West  => { todo!() },
+                South => { y           = y.plus(layout.h());
+                           h_remaining = h_remaining.minus(layout.h());
+                           h_used      = h_used.plus(layout.h());
+                           to.place(layout, component); },
+                East  => { x           = x.plus(layout.w());
+                           w_remaining = w_remaining.minus(layout.w());
+                           w_used      = w_used.plus(layout.h());
+                           to.place(layout, component); },
             }
         });
     }