diff --git a/src/compiler.rs b/src/compiler.rs
index b0b8a57..31a25df 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -10,7 +10,7 @@ use cfg_if::cfg_if;
 use derive_new::new;
 use derive_wrapper::{AsRef, From};
 use fasteval::{Compiler as _, EvalNamespace, Evaler, Instruction, Slab};
-use log::trace;
+use log::{debug, trace};
 use thiserror::Error;
 
 cfg_if! {
@@ -74,7 +74,7 @@ pub struct Silence;
 
 impl Token for Silence {
     fn apply(&self, context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         let (mut context, mut next) = context.render(None)?;
         context.result.append(&mut next);
         Ok(context)
@@ -87,7 +87,7 @@ pub struct Marker;
 
 impl Token for Marker {
     fn apply(&self, mut context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         context.result.clear();
         Ok(context)
     }
@@ -99,7 +99,7 @@ pub struct Note(pub u8);
 
 impl Token for Note {
     fn apply(&self, context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         let (mut context, mut next) = context.render(Some(self.0))?;
         context.result.append(&mut next);
         Ok(context)
@@ -118,7 +118,7 @@ impl AsRef<VariableChange> for VariableChange {
 
 impl Token for VariableChange {
     fn apply(&self, mut context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         *context.get_mut(self.0.to_string())? = context.eval(self.1.as_ref())?;
         Ok(context)
     }
@@ -143,7 +143,7 @@ impl Default for LoopCount {
 
 impl Token for Loop {
     fn apply(&self, mut context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         let mut old_result = context.result.clone();
         let count = match self.0 {
             LoopCount::Litteral(n) => n,
@@ -169,7 +169,7 @@ pub struct Tuplet(pub TokenVec);
 
 impl Token for Tuplet {
     fn apply(&self, mut context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         let mut old_result = context.result.clone();
         context.result.clear();
         let mut new_context = self
@@ -207,7 +207,7 @@ pub struct Slope(pub VariableChange, pub TokenVec);
 
 impl Token for Slope {
     fn apply(&self, mut context: Context) -> Result<Context, CompilerError> {
-        trace!("⚡ {}", type_name::<Self>());
+        debug!("⚡ {}", type_name::<Self>());
         context.slopes.push((
             self.0.as_ref().0.to_string(),
             self.0.as_ref().1.as_ref().clone(),
@@ -402,13 +402,16 @@ impl Context {
 
     pub fn eval_with(
         Expression {
-            from: _,
+            from,
             instruction,
             slab,
         }: &Expression,
         ns: &mut impl EvalNamespace,
     ) -> Result<f64, fasteval::Error> {
-        instruction.eval(slab, ns)
+        instruction
+            .eval(slab, ns)
+            .inspect(|ok| trace!("{from} = {ok}"))
+            .inspect_err(|e| trace!("{from} = {e}"))
     }
 
     pub fn render(mut self, n: Option<u8>) -> Result<(Self, Vec<f64>), CompilerError> {
diff --git a/src/parser.rs b/src/parser.rs
index 2aef237..b7ef122 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -74,7 +74,7 @@ where
     SV: Borrow<VariableChange>,
     V: AsRef<[char]>,
 {
-    debug!("making the TOKEN parser");
+    trace!("making the TOKEN parser");
     let space_or_comment = || {
         value(
             (),
@@ -107,7 +107,7 @@ impl Silence {
         I: Input,
         <I as Input>::Item: AsChar,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         value(Self, char('.'))
     }
 }
@@ -118,7 +118,7 @@ impl Marker {
         I: Input,
         <I as Input>::Item: AsChar,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         value(Marker, char('%'))
     }
 }
@@ -132,7 +132,7 @@ impl Note {
         NS: AsRef<str>,
         I: Input + for<'z> Compare<&'z str>,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         let notes = {
             let mut sorted = notes
                 .into_iter()
@@ -167,7 +167,7 @@ impl VariableChange {
         <I as Input>::Item: AsChar,
         V: AsRef<[char]>,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         move |i: I| {
             preceded(
                 char('$'),
@@ -195,7 +195,7 @@ impl Loop {
         SV: Borrow<VariableChange>,
         V: AsRef<[char]>,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         move |input| {
             delimited(
                 char('('),
@@ -235,7 +235,7 @@ impl Tuplet {
         SV: Borrow<VariableChange>,
         V: AsRef<[char]>,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         |input| {
             delimited(char('['), token_parser(parser), char(']'))
                 .map(Self)
@@ -259,7 +259,7 @@ impl Slope {
         SV: Borrow<VariableChange>,
         V: AsRef<[char]>,
     {
-        debug!("making the {} parser", type_name::<Self>());
+        trace!("making the {} parser", type_name::<Self>());
         move |input| {
             let slopes = {
                 let mut vec = parser
@@ -300,7 +300,7 @@ where
     V: IntoIterator<Item = C>,
     C: Borrow<char>,
 {
-    debug!("making the Expression parser");
+    trace!("making the Expression parser");
     let variables: Vec<(String, f64)> = variables
         .into_iter()
         .map(|v| (v.borrow().to_string(), 0.0))
@@ -347,7 +347,7 @@ where
     I: Input + Copy,
     F: Fn(I) -> Option<O>,
 {
-    debug!("making take_while_map parser");
+    trace!("making take_while_map parser");
     move |input: I| {
         let mut len = input.input_len();
         debug!(