diff --git a/src/std.rs b/src/std.rs
index 8821a3d..e1e0eaa 100644
--- a/src/std.rs
+++ b/src/std.rs
@@ -7,6 +7,7 @@ pub mod inlining;
 mod local_origin;
 pub mod nullable;
 pub mod point;
+pub mod tracing;
 mod typeless;
 
 use std::{error::Error, fmt::Display, rc::Rc};
diff --git a/src/std/collections/stack.rs b/src/std/collections/stack.rs
index b2b5a07..eac33fc 100644
--- a/src/std/collections/stack.rs
+++ b/src/std/collections/stack.rs
@@ -274,10 +274,12 @@ mod tests {
         let traced = stack.clone().vec();
         assert_eq!(traced.length(), 0);
         assert_eq!(traced.width(), 0);
+        assert_eq!(format!("{}", traced.t), ".");
         let stack: T<TestContextTraced> = Rc::new(stack).trace()?;
         let traced = stack.clone().vec();
         assert_eq!(traced.length(), 3);
         assert_eq!(traced.width(), 1);
+        assert_eq!(format!("{}", traced.t), "( ? -> ? -> ? )");
         Ok(())
     }
 }
diff --git a/src/std/tracing.rs b/src/std/tracing.rs
new file mode 100644
index 0000000..4364a45
--- /dev/null
+++ b/src/std/tracing.rs
@@ -0,0 +1,189 @@
+mod trace;
+mod traced;
+
+use crate::core::*;
+use crate::func::*;
+use trace::*;
+pub use traced::Traced;
+
+pub struct TracedDiagnostic;
+
+pub struct TracedClass;
+
+trait WithTrace: Sized {
+    fn with_trace(self, t: TraceBox) -> Traced<Self>;
+}
+
+impl<A> WithTrace for A {
+    fn with_trace(self, t: TraceBox) -> Traced<Self> {
+        Traced { a: self, t }
+    }
+}
+
+impl<A> Traced<A> {
+    pub fn wrapped(self, event: &str) -> Self {
+        Traced {
+            a: self.a,
+            t: self.t.wrapped(event),
+        }
+    }
+
+    pub fn after_resolution(self) -> Self {
+        self.after(TraceBox::resolution())
+    }
+
+    fn after(self, t: TraceBox) -> Self {
+        Traced {
+            a: self.a,
+            t: self.t.after(t),
+        }
+    }
+
+    fn before(self, t: TraceBox) -> Self {
+        Traced {
+            a: self.a,
+            t: self.t.before(t),
+        }
+    }
+
+    pub fn length(&self) -> usize {
+        self.t.length()
+    }
+
+    pub fn width(&self) -> usize {
+        self.t.width()
+    }
+}
+
+impl WeakFunctor for TracedClass {
+    type F<'a, A: 'a> = Traced<A>;
+}
+
+impl Functor for TracedClass {
+    fn fmap<'a, A: 'a, B: 'a>(f: impl 'a + FnOnce(A) -> B, fa: Self::F<'a, A>) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        f(fa.a).with_trace(fa.t)
+    }
+
+    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        b.with_trace(fa.t)
+    }
+
+    fn void<'a, A: 'a>(fa: Self::F<'a, A>) -> Self::F<'a, ()>
+    where
+        Self: 'a,
+    {
+        ().with_trace(fa.t)
+    }
+}
+
+impl ApplicativeSeq for TracedClass {
+    fn seq<'a, A: 'a, B: 'a>(
+        ff: Self::F<'a, impl 'a + FnOnce(A) -> B>,
+        fa: Self::F<'a, A>,
+    ) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        (ff.a)(fa.a).with_trace(TraceBox::parallel(ff.t, fa.t))
+    }
+}
+
+impl ApplicativeLA2 for TracedClass {
+    fn la2<'a, A: 'a, B: 'a, C: 'a>(
+        f: impl 'a + FnOnce(A, B) -> C,
+        fa: Self::F<'a, A>,
+        fb: Self::F<'a, B>,
+    ) -> Self::F<'a, C>
+    where
+        Self: 'a,
+    {
+        f(fa.a, fb.a).with_trace(TraceBox::parallel(fa.t, fb.t))
+    }
+}
+
+impl ApplicativeTuple for TracedClass {
+    fn tuple<'a, A: 'a, B: 'a>((fa, fb): (Self::F<'a, A>, Self::F<'a, B>)) -> Self::F<'a, (A, B)>
+    where
+        Self: 'a,
+    {
+        (fa.a, fb.a).with_trace(TraceBox::parallel(fa.t, fb.t))
+    }
+}
+
+impl Applicative for TracedClass {
+    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A> {
+        a.with_trace(TraceBox::pure())
+    }
+
+    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        fb.a.with_trace(TraceBox::parallel(fa.t, fb.t))
+    }
+
+    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A>
+    where
+        Self: 'a,
+    {
+        fa.a.with_trace(TraceBox::parallel(fa.t, fb.t))
+    }
+}
+
+impl Monad for TracedClass {
+    fn bind<'a, A: 'a, B: 'a>(
+        fa: Self::F<'a, A>,
+        f: impl 'a + FnOnce(A) -> Self::F<'a, B>,
+    ) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        f(fa.a).after(fa.t)
+    }
+
+    fn ibind<'a, A: 'a, B: 'a>(
+        mut a: A,
+        mut f: impl 'a + FnMut(A) -> Self::F<'a, IState<A, B>>,
+    ) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
+        let mut t = TraceBox::pure();
+        loop {
+            let fa = f(a);
+            t = fa.t.after(t);
+            match fa.a {
+                IState::Pending(next_a) => a = next_a,
+                IState::Done(b) => return b.with_trace(t),
+            }
+        }
+    }
+
+    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
+    where
+        Self::F<'a, A>: 'a,
+        Self: 'a,
+    {
+        ffa.a.after(ffa.t)
+    }
+}
+
+impl Diagnostic<TracedClass> for TracedDiagnostic {
+    fn after<A>(fa: Traced<A>, event: &str) -> Traced<A> {
+        fa.after(TraceBox::event(event))
+    }
+
+    fn before<A>(fa: Traced<A>, event: &str) -> Traced<A> {
+        fa.before(TraceBox::event(event))
+    }
+
+    fn wrapped<A>(fa: Traced<A>, event: &str) -> Traced<A> {
+        fa.wrapped(event)
+    }
+}
diff --git a/src/std/tracing/trace.rs b/src/std/tracing/trace.rs
new file mode 100644
index 0000000..b07d46a
--- /dev/null
+++ b/src/std/tracing/trace.rs
@@ -0,0 +1,178 @@
+use std::{cmp::max, fmt::Display};
+
+#[derive(Debug)]
+enum Trace {
+    Pure,
+    InvolvesOneResolution,
+    Event(String),
+    Parallel(TraceBox, TraceBox),
+    Sequential { first: TraceBox, second: TraceBox },
+    Wrapped { name: String, trace: TraceBox },
+}
+
+#[derive(Debug)]
+pub struct TraceBox {
+    trace: Box<Trace>,
+}
+
+impl Trace {
+    fn fmt_parallel(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Trace::Parallel(a, b) => {
+                f.write_fmt(format_args!("{} | {}", ParallelBox(a), ParallelBox(b)))
+            }
+            trace @ _ => f.write_fmt(format_args!("{}", trace)),
+        }
+    }
+
+    fn fmt_sequential(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Trace::Sequential { first, second } => f.write_fmt(format_args!(
+                "{} -> {}",
+                SequentialBox(first),
+                SequentialBox(second)
+            )),
+            trace @ _ => f.write_fmt(format_args!("{}", trace)),
+        }
+    }
+}
+
+struct ParallelBox<'a>(&'a TraceBox);
+
+struct SequentialBox<'a>(&'a TraceBox);
+
+impl<'a> Display for ParallelBox<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.trace.fmt_parallel(f)
+    }
+}
+
+impl<'a> Display for SequentialBox<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.trace.fmt_sequential(f)
+    }
+}
+
+impl Display for Trace {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Trace::Pure => f.write_fmt(format_args!(".")),
+            Trace::InvolvesOneResolution => f.write_fmt(format_args!("?")),
+            Trace::Event(event) => f.write_fmt(format_args!("{}", event)),
+            Trace::Parallel(a, b) => {
+                f.write_fmt(format_args!("( {} | {} )", ParallelBox(a), ParallelBox(b)))
+            }
+            Trace::Sequential { first, second } => f.write_fmt(format_args!(
+                "( {} -> {} )",
+                SequentialBox(first),
+                SequentialBox(second)
+            )),
+            Trace::Wrapped { name, trace } => f.write_fmt(format_args!("{} @ {}", name, trace)),
+        }
+    }
+}
+
+impl Display for TraceBox {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!("{}", self.trace))
+    }
+}
+
+impl From<Trace> for TraceBox {
+    fn from(value: Trace) -> Self {
+        TraceBox {
+            trace: value.into(),
+        }
+    }
+}
+
+impl From<TraceBox> for Trace {
+    fn from(value: TraceBox) -> Self {
+        *value.trace
+    }
+}
+
+impl Trace {
+    fn sequential(ta: Self, tb: Self) -> Self {
+        match (ta, tb) {
+            (Trace::Pure, a) => a,
+            (a, Trace::Pure) => a,
+            (a, b) => Trace::Sequential {
+                first: a.into(),
+                second: b.into(),
+            },
+        }
+    }
+
+    fn length(&self) -> usize {
+        match self {
+            Self::Pure => 0,
+            Self::InvolvesOneResolution => 1,
+            Self::Event(_) => 0,
+            Self::Parallel(a, b) => max(a.length(), b.length()),
+            Self::Sequential { first, second } => first.length() + second.length(),
+            Self::Wrapped { trace, .. } => trace.length(),
+        }
+    }
+
+    fn width(&self) -> usize {
+        match self {
+            Self::Pure => 0,
+            Self::InvolvesOneResolution => 1,
+            Self::Event(_) => 0,
+            Self::Parallel(a, b) => a.width() + b.width(),
+            Self::Sequential { first, second } => max(first.width(), second.width()),
+            Self::Wrapped { trace, .. } => trace.width(),
+        }
+    }
+
+    fn parallel(ta: Self, tb: Self) -> Self {
+        match (ta, tb) {
+            (Trace::Pure, a) => a,
+            (a, Trace::Pure) => a,
+            (a, b) => Trace::Parallel(a.into(), b.into()),
+        }
+    }
+}
+
+impl TraceBox {
+    pub fn pure() -> Self {
+        Trace::Pure.into()
+    }
+
+    pub fn resolution() -> Self {
+        Trace::InvolvesOneResolution.into()
+    }
+
+    pub fn event(event: &str) -> Self {
+        Trace::Event(event.into()).into()
+    }
+
+    pub fn wrapped(self, event: &str) -> Self {
+        Trace::Wrapped {
+            name: event.into(),
+            trace: self,
+        }
+        .into()
+    }
+
+    pub fn after(self, t: Self) -> Self {
+        Trace::sequential(t.into(), self.into()).into()
+    }
+
+    pub fn before(self, t: Self) -> Self {
+        Trace::sequential(self.into(), t.into()).into()
+    }
+
+    pub fn parallel(ta: Self, tb: Self) -> Self {
+        Trace::parallel(ta.into(), tb.into()).into()
+    }
+
+    pub fn length(&self) -> usize {
+        self.trace.length()
+    }
+
+    pub fn width(&self) -> usize {
+        self.trace.width()
+    }
+}
diff --git a/src/std/tracing/traced.rs b/src/std/tracing/traced.rs
new file mode 100644
index 0000000..0df3391
--- /dev/null
+++ b/src/std/tracing/traced.rs
@@ -0,0 +1,6 @@
+use super::trace::*;
+
+pub struct Traced<A> {
+    pub a: A,
+    pub t: TraceBox,
+}
diff --git a/src/testing/traced.rs b/src/testing/traced.rs
index 9d8ff24..ac9a22e 100644
--- a/src/testing/traced.rs
+++ b/src/testing/traced.rs
@@ -1,10 +1,7 @@
-use std::cmp::max;
-
 use super::*;
 use crate::core::*;
 use crate::func::*;
-
-pub struct TracedDiagnostic;
+use crate::std::tracing::*;
 
 pub struct TestContextTraced;
 
@@ -20,263 +17,6 @@ impl Context for TestContextTraced {
     }
 }
 
-pub struct TracedClass;
-
-pub enum Trace {
-    Pure,
-    InvolvesOneResolution,
-    Event(String),
-    Parallel(Box<Trace>, Box<Trace>),
-    Sequential {
-        first: Box<Trace>,
-        second: Box<Trace>,
-    },
-    Wrapped {
-        name: String,
-        trace: Box<Trace>,
-    },
-}
-
-pub struct Traced<A> {
-    a: A,
-    t: Box<Trace>,
-}
-
-trait WithTrace: Sized {
-    fn with_trace(self, t: Box<Trace>) -> Traced<Self>;
-}
-
-impl<A> WithTrace for A {
-    fn with_trace(self, t: Box<Trace>) -> Traced<Self> {
-        Traced { a: self, t }
-    }
-}
-
-impl Trace {
-    fn pure() -> Box<Self> {
-        Self::Pure.into()
-    }
-
-    fn resolution() -> Box<Self> {
-        Self::InvolvesOneResolution.into()
-    }
-
-    fn event(event: &str) -> Box<Self> {
-        Self::Event(event.into()).into()
-    }
-
-    fn wrapped(self: Box<Self>, event: &str) -> Box<Self> {
-        Self::Wrapped {
-            name: event.into(),
-            trace: self,
-        }
-        .into()
-    }
-
-    fn after(self: Box<Self>, t: Box<Self>) -> Box<Self> {
-        match (*self, *t) {
-            (Self::Pure, a) => a.into(),
-            (a, Self::Pure) => a.into(),
-            (a, b) => Self::Sequential {
-                first: b.into(),
-                second: a.into(),
-            }
-            .into(),
-        }
-    }
-
-    fn before(self: Box<Self>, t: Box<Self>) -> Box<Self> {
-        match (*self, *t) {
-            (Self::Pure, a) => a.into(),
-            (a, Self::Pure) => a.into(),
-            (a, b) => Self::Sequential {
-                first: a.into(),
-                second: b.into(),
-            }
-            .into(),
-        }
-    }
-
-    fn parallel(ta: Box<Self>, tb: Box<Self>) -> Box<Self> {
-        match (*ta, *tb) {
-            (Self::Pure, a) => a.into(),
-            (a, Self::Pure) => a.into(),
-            (a, b) => Self::Parallel(a.into(), b.into()).into(),
-        }
-    }
-
-    fn length(&self) -> usize {
-        match self {
-            Self::Pure => 0,
-            Self::InvolvesOneResolution => 1,
-            Self::Event(_) => 0,
-            Self::Parallel(a, b) => max(a.length(), b.length()),
-            Self::Sequential { first, second } => first.length() + second.length(),
-            Self::Wrapped { name: _, trace } => trace.length(),
-        }
-    }
-
-    fn width(&self) -> usize {
-        match self {
-            Self::Pure => 0,
-            Self::InvolvesOneResolution => 1,
-            Self::Event(_) => 0,
-            Self::Parallel(a, b) => a.width() + b.width(),
-            Self::Sequential { first, second } => max(first.width(), second.width()),
-            Self::Wrapped { name: _, trace } => trace.width(),
-        }
-    }
-}
-
-impl<A> Traced<A> {
-    fn wrapped(self, event: &str) -> Self {
-        Traced {
-            a: self.a,
-            t: self.t.wrapped(event),
-        }
-    }
-    fn after(self, t: Box<Trace>) -> Self {
-        Traced {
-            a: self.a,
-            t: self.t.after(t),
-        }
-    }
-
-    fn before(self, t: Box<Trace>) -> Self {
-        Traced {
-            a: self.a,
-            t: self.t.before(t),
-        }
-    }
-
-    pub fn length(&self) -> usize {
-        self.t.length()
-    }
-
-    pub fn width(&self) -> usize {
-        self.t.width()
-    }
-}
-
-impl WeakFunctor for TracedClass {
-    type F<'a, A: 'a> = Traced<A>;
-}
-
-impl Functor for TracedClass {
-    fn fmap<'a, A: 'a, B: 'a>(f: impl 'a + FnOnce(A) -> B, fa: Self::F<'a, A>) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        f(fa.a).with_trace(fa.t)
-    }
-
-    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        b.with_trace(fa.t)
-    }
-
-    fn void<'a, A: 'a>(fa: Self::F<'a, A>) -> Self::F<'a, ()>
-    where
-        Self: 'a,
-    {
-        ().with_trace(fa.t)
-    }
-}
-
-impl ApplicativeSeq for TracedClass {
-    fn seq<'a, A: 'a, B: 'a>(
-        ff: Self::F<'a, impl 'a + FnOnce(A) -> B>,
-        fa: Self::F<'a, A>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        (ff.a)(fa.a).with_trace(Trace::parallel(ff.t, fa.t))
-    }
-}
-
-impl ApplicativeLA2 for TracedClass {
-    fn la2<'a, A: 'a, B: 'a, C: 'a>(
-        f: impl 'a + FnOnce(A, B) -> C,
-        fa: Self::F<'a, A>,
-        fb: Self::F<'a, B>,
-    ) -> Self::F<'a, C>
-    where
-        Self: 'a,
-    {
-        f(fa.a, fb.a).with_trace(Trace::parallel(fa.t, fb.t))
-    }
-}
-
-impl ApplicativeTuple for TracedClass {
-    fn tuple<'a, A: 'a, B: 'a>((fa, fb): (Self::F<'a, A>, Self::F<'a, B>)) -> Self::F<'a, (A, B)>
-    where
-        Self: 'a,
-    {
-        (fa.a, fb.a).with_trace(Trace::parallel(fa.t, fb.t))
-    }
-}
-
-impl Applicative for TracedClass {
-    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A> {
-        a.with_trace(Trace::pure())
-    }
-
-    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        fb.a.with_trace(Trace::parallel(fa.t, fb.t))
-    }
-
-    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A>
-    where
-        Self: 'a,
-    {
-        fa.a.with_trace(Trace::parallel(fa.t, fb.t))
-    }
-}
-
-impl Monad for TracedClass {
-    fn bind<'a, A: 'a, B: 'a>(
-        fa: Self::F<'a, A>,
-        f: impl 'a + FnOnce(A) -> Self::F<'a, B>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        f(fa.a).after(fa.t)
-    }
-
-    fn ibind<'a, A: 'a, B: 'a>(
-        mut a: A,
-        mut f: impl 'a + FnMut(A) -> Self::F<'a, IState<A, B>>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        let mut t = Trace::pure();
-        loop {
-            let fa = f(a);
-            t = fa.t.after(t);
-            match fa.a {
-                IState::Pending(next_a) => a = next_a,
-                IState::Done(b) => return b.with_trace(t),
-            }
-        }
-    }
-
-    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
-        Self: 'a,
-    {
-        ffa.a.after(ffa.t)
-    }
-}
-
 struct TracedResolver<'a> {
     resolver: Rc<dyn Resolver<'a, TestContextTraced>>,
 }
@@ -300,7 +40,7 @@ impl<'a> Resolver<'a, TestContextTraced> for TracedResolver<'a> {
             },
             self.resolver.clone().resolve(address),
         )
-        .after(Trace::resolution())
+        .after_resolution()
     }
 }
 
@@ -314,17 +54,3 @@ impl<'a, A: Mentionable<'a, TestContextTraced>> Traceable<'a> for A {
         TypelessMentionable::from_typed(self).cast_full(factory, TracedResolver::new)
     }
 }
-
-impl Diagnostic<TracedClass> for TracedDiagnostic {
-    fn after<'a, A>(fa: Traced<A>, event: &'a str) -> Traced<A> {
-        fa.after(Trace::event(event))
-    }
-
-    fn before<'a, A>(fa: Traced<A>, event: &'a str) -> Traced<A> {
-        fa.before(Trace::event(event))
-    }
-
-    fn wrapped<'a, A>(fa: Traced<A>, event: &'a str) -> Traced<A> {
-        fa.wrapped(event)
-    }
-}