1 files changed, 19 insertions, 7 deletions

diff --git a/subprojects/frontend/src/language/problem.grammar b/subprojects/frontend/src/language/problem.grammar
index ce3baa02..b69ee73f 100644
--- a/subprojects/frontend/src/language/problem.grammar
+++ b/subprojects/frontend/src/language/problem.grammar
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2021-2024 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
@@ -22,13 +22,16 @@
 @top Problem { statement* }
 
 statement {
+  ImportStatement {
+    kw<"import"> ModuleName (kw<"as"> ModuleName)? "."
+  } |
   Assertion {
     kw<"default">? (NotOp | UnknownOp)? RelationName
     ParameterList<AssertionArgument>
     (":" Expr)? "."
   } |
   ProblemDeclaration {
-    kw<"problem"> QualifiedName "."
+    (ckw<"module"> | kw<"problem">) ModuleName "."
   } |
   ClassDefinition {
     kw<"abstract">? kw<"class"> RelationName
@@ -37,7 +40,7 @@ statement {
   } |
   EnumDefinition {
     kw<"enum"> RelationName
-    (EnumBody { "{" sep<",", IndividualNodeName> "}" } | ".")
+    (EnumBody { "{" sep<",", AtomNodeName> "}" } | ".")
   } |
   PredicateDefinition {
     (
@@ -56,8 +59,11 @@ statement {
   //  RuleName ParameterList<Parameter>?
   //  RuleBody { ":" sep<OrOp, Conjunction> "==>" sep<OrOp, Consequent> "." }
   //} |
-  IndividualDeclaration {
-    kw<"indiv"> sep<",", IndividualNodeName> "."
+  AtomDeclaration {
+    kw<"declare">? ckw<"atom"> sep<",", AtomNodeName> "."
+  } |
+  NodeDeclaration {
+    (kw<"declare"> | kw<"declare">? ckw<"multi">) sep<",", NodeName> "."
   } |
   ScopeDeclaration {
     kw<"scope"> sep<",", ScopeElement> "."
@@ -161,13 +167,15 @@ RelationName { QualifiedName ~name }
 
 //RuleName { QualifiedName }
 
-IndividualNodeName { QualifiedName }
+AtomNodeName { QualifiedName }
 
 VariableName[@dynamicPrecedence=10] { QualifiedName ~name }
 
 NodeName { QualifiedName }
 
-QualifiedName[implicitCompletion=true] { identifier ("::" identifier)* }
+ModuleName { QualifiedName }
+
+QualifiedName[implicitCompletion=true] { "::"? identifier (QualifiedNameSeparator "::" identifier)* }
 
 kw<term> { @specialize[@name={term},implicitCompletion=true]<identifier, term> }
 
@@ -181,6 +189,10 @@ sep1<separator, content> { content (separator content)* }
 
 @skip { LineComment | BlockComment | whitespace }
 
+@external tokens qualifiedNameSeparator from "./tokens" {
+  QualifiedNameSeparator
+}
+
 @tokens {
   whitespace { std.whitespace+ }