diff --git a/AGENTS.md b/AGENTS.md
index 04682324..4590e6dd 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -6,7 +6,7 @@
 
 # Documentation
 
-[docs/README.md](docs/README.md) | [CLI Guide](docs/cli.md) | [Language Reference](docs/lang-reference.md) | [Type System](docs/type-system.md) | [Runtime Engine](docs/runtime-engine.md) | [Binary Format](docs/binary-format/01-overview.md)
+[docs/README.md](docs/README.md) | [CLI Guide](docs/cli.md) | [Language Reference](docs/lang-reference.md) | [Type System](docs/type-system.md) | [Runtime Engine](docs/runtime-engine.md) | [Tree Navigation](docs/tree-navigation.md) | [Binary Format](docs/binary-format/01-overview.md)
 
 # Query Syntax Quick Reference
 
@@ -22,7 +22,7 @@
 | `@x :: T`           | Type annotation                |
 | `@x :: string`      | Extract node text              |
 | `field: pattern`    | Field constraint               |
-| `!field`            | Negated field (assert absent)  |
+| `-field`            | Negated field (assert absent)  |
 | `?` `*` `+`         | Quantifiers (0-1, 0+, 1+)      |
 | `??` `*?` `+?`      | Non-greedy variants            |
 | `.`                 | Anchor (adjacency, see below)  |
@@ -146,7 +146,7 @@ Tree-sitter: `((a) (b))` — Plotnik: `{(a) (b)}`. The #1 syntax error.
 crates/
   plotnik-cli/         # CLI tool
     src/commands/      # Subcommands (ast, check, dump, exec, infer, trace, langs)
-  plotnik-core/        # Common code (Interner, Symbol)
+  plotnik-core/        # Node type database (NodeTypes, StaticNodeTypes) and string interning (Interner, Symbol)
   plotnik-lib/         # Plotnik as library
     src/
       analyze/         # Semantic analysis (symbol_table, dependencies, type_check, validation)
diff --git a/crates/plotnik-lib/src/analyze/recursion.rs b/crates/plotnik-lib/src/analyze/recursion.rs
index e2783459..638b4607 100644
--- a/crates/plotnik-lib/src/analyze/recursion.rs
+++ b/crates/plotnik-lib/src/analyze/recursion.rs
@@ -92,12 +92,12 @@ impl<'a, 'd> RecursionValidator<'a, 'd> {
 
     /// Finds a cycle within the given set of nodes (SCC).
     /// `get_edge_location` returns the location of a reference from `expr` to `target`.
-    fn find_cycle<'s>(
+    fn find_cycle<'b>(
         &self,
-        nodes: &'s [String],
-        domain: &IndexSet<&'s str>,
+        nodes: &'b [String],
+        domain: &IndexSet<&'b str>,
         get_edge_location: impl Fn(&Self, SourceId, &Expr, &str) -> Option<TextRange>,
-    ) -> Option<Vec<(SourceId, TextRange, &'s str)>> {
+    ) -> Option<Vec<(SourceId, TextRange, &'b str)>> {
         let mut adj = IndexMap::new();
         for name in nodes {
             if let Some((source_id, body)) = self.symbol_table.get_full(name) {
diff --git a/crates/plotnik-lib/src/analyze/symbol_table.rs b/crates/plotnik-lib/src/analyze/symbol_table.rs
index e83fdc7f..a7afcce7 100644
--- a/crates/plotnik-lib/src/analyze/symbol_table.rs
+++ b/crates/plotnik-lib/src/analyze/symbol_table.rs
@@ -135,11 +135,11 @@ pub fn resolve_names(
     symbol_table
 }
 
-struct ReferenceResolver<'q, 'd, 't> {
+struct ReferenceResolver<'q, 'd, 'a> {
     src: &'q str,
     source_id: SourceId,
     diag: &'d mut Diagnostics,
-    symbol_table: &'t mut SymbolTable,
+    symbol_table: &'a mut SymbolTable,
 }
 
 impl Visitor for ReferenceResolver<'_, '_, '_> {
@@ -172,10 +172,10 @@ impl Visitor for ReferenceResolver<'_, '_, '_> {
     }
 }
 
-struct ReferenceValidator<'d, 't> {
+struct ReferenceValidator<'d, 'a> {
     source_id: SourceId,
     diag: &'d mut Diagnostics,
-    symbol_table: &'t SymbolTable,
+    symbol_table: &'a SymbolTable,
 }
 
 impl Visitor for ReferenceValidator<'_, '_> {
diff --git a/crates/plotnik-lib/src/analyze/type_check/mod.rs b/crates/plotnik-lib/src/analyze/type_check/mod.rs
index fd79a41d..509a5ef9 100644
--- a/crates/plotnik-lib/src/analyze/type_check/mod.rs
+++ b/crates/plotnik-lib/src/analyze/type_check/mod.rs
@@ -14,7 +14,7 @@ mod context_tests;
 #[cfg(test)]
 mod symbol_tests;
 #[cfg(test)]
-mod tests;
+mod type_check_tests;
 #[cfg(test)]
 mod unify_tests;
 
diff --git a/crates/plotnik-lib/src/analyze/type_check/tests.rs b/crates/plotnik-lib/src/analyze/type_check/type_check_tests.rs
similarity index 100%
rename from crates/plotnik-lib/src/analyze/type_check/tests.rs
rename to crates/plotnik-lib/src/analyze/type_check/type_check_tests.rs
diff --git a/crates/plotnik-lib/src/engine/materializer.rs b/crates/plotnik-lib/src/engine/materializer.rs
index 88ac3ff4..f0dd678c 100644
--- a/crates/plotnik-lib/src/engine/materializer.rs
+++ b/crates/plotnik-lib/src/engine/materializer.rs
@@ -13,14 +13,14 @@ pub trait Materializer<'t> {
 }
 
 /// Materializer that produces Value with resolved strings.
-pub struct ValueMaterializer<'ctx> {
-    source: &'ctx str,
-    types: TypesView<'ctx>,
-    strings: StringsView<'ctx>,
+pub struct ValueMaterializer<'a> {
+    source: &'a str,
+    types: TypesView<'a>,
+    strings: StringsView<'a>,
 }
 
-impl<'ctx> ValueMaterializer<'ctx> {
-    pub fn new(source: &'ctx str, types: TypesView<'ctx>, strings: StringsView<'ctx>) -> Self {
+impl<'a> ValueMaterializer<'a> {
+    pub fn new(source: &'a str, types: TypesView<'a>, strings: StringsView<'a>) -> Self {
         Self {
             source,
             types,