diff --git a/dsl/src/dsl.rs b/dsl/src/dsl.rs
index 3859210..823dc74 100644
--- a/dsl/src/dsl.rs
+++ b/dsl/src/dsl.rs
@@ -248,21 +248,21 @@ pub trait DslNs<'t, T: 't>: 't {
     /// Known expressions.
     const EXPRS: DslExprs<'t, Self, T> = DslNsMap::new(&[]);
     /// Resolve an expression or symbol.
-    fn from <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
-        if let Ok(Some(literal)) = self.from_literal(dsl) {
+    fn from (&'t self, dsl: impl Dsl) -> Perhaps<T> {
+        if let Ok(Some(literal)) = self.from_literal(&dsl) {
             Ok(Some(literal))
-        } else if let Ok(Some(meaning)) = self.from_word(dsl) {
+        } else if let Ok(Some(meaning)) = self.from_word(&dsl) {
             Ok(Some(meaning))
         } else {
-            self.from_expr(dsl)
+            self.from_expr(&dsl)
         }
     }
     /// Resolve as literal if valid.
-    fn from_literal <D: Dsl> (&self, _: &D) -> Perhaps<T> {
+    fn from_literal (&self, _: impl Dsl) -> Perhaps<T> {
         Ok(None)
     }
     /// Resolve a symbol if known.
-    fn from_word <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
+    fn from_word (&'t self, dsl: impl Dsl) -> Perhaps<T> {
         if let Some(dsl) = dsl.word()? {
             for (key, get) in Self::WORDS.0.iter() {
                 if dsl == *key {
@@ -274,7 +274,7 @@ pub trait DslNs<'t, T: 't>: 't {
         return Ok(None)
     }
     /// Resolve an expression if known.
-    fn from_expr <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
+    fn from_expr (&'t self, dsl: impl Dsl) -> Perhaps<T> {
         if let Some(expr) = dsl.expr()? {
             for (key, get) in Self::EXPRS.0.iter() {
                 if Some(*key) == expr.head()? {
diff --git a/dsl/src/dsl_macros.rs b/dsl/src/dsl_macros.rs
index 36d2c36..f4460f3 100644
--- a/dsl/src/dsl_macros.rs
+++ b/dsl/src/dsl_macros.rs
@@ -95,7 +95,7 @@
                 $(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
             const EXPRS: DslExprs<'t, $State, $Type> = DslNsMap::new(&[
                 $(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
-            fn from_literal <D: Dsl> (&self, dsl: &D) -> Perhaps<$Type> {
+            fn from_literal (&self, dsl: impl Dsl) -> Perhaps<$Type> {
                 Ok(if let Some(src) = dsl.src()? {
                     Some(to_number(src)? as $Type)
                 } else {