smallest change to make PROBLEM reappear

Author: bblfish

scala/RDF.scala

@@ -11,22 +11,31 @@ trait RDF:
   rdf =>
 
   type R = rdf.type
-  
-  type Node <: Matchable
-  type URI <: Node
+  type rNode <: Matchable
+  type rURI <: rNode
+  type Node <: rNode
+  type URI <: Node & rURI
 
   given rops: ROps[R]
 end RDF
 
 object RDF:
+  
+  type rNode[R <: RDF] = R match
+    case GetRelativeNode[n] => n & Matchable
+  
+  type rURI[R <: RDF] = R match
+    case GetRelativeURI[u] => u & rNode[R]
 
   type Node[R <: RDF] = R match
-    case GetNode[n] => n
+    case GetNode[n] => n & rNode[R]
 
   type URI[R <: RDF] <: Node[R] = R match
-    case GetURI[u] => u & Node[R]
-
+    case GetURI[u] => u & Node[R] & rURI[R]
+  
+  private type GetRelativeNode[N] = RDF { type rNode = N }
   private type GetNode[N] = RDF { type Node = N }
+  private type GetRelativeURI[U] = RDF { type rURI = U }
   private type GetURI[U] = RDF { type URI = U }
 
 end RDF

scala/RDF_Class.scala

@@ -24,9 +24,11 @@ object ClassTypes {
 object ClassRDF extends generic.RDF:
   import class_based.ClassTypes as cz
   import generic.*
-
-  override opaque type Node <: Matchable = cz.Node
-  override opaque type URI <: Node = cz.Uri
+  
+  override opaque type rNode <: Matchable = cz.Node
+  override opaque type rURI <: rNode = cz.Uri
+  override opaque type Node <: rNode = cz.Node
+  override opaque type URI <: Node & rURI = cz.Uri
 
   given rops: generic.ROps[R] with
     override def mkUri(str: String): Try[RDF.URI[R]] = Try(

scala/RDF_UsingScalaTrait.scala

@@ -8,8 +8,10 @@ import generic.*
 // todo, put back example using traits only to see if Java is the problem
 object TraitBasedRDF extends RDF:
   lazy val factory: rdfscala.ScalaMkNodes = rdfscala.SimpleScalaNodeFactory
-  override opaque type Node <: Matchable = rdfscala.TstNode
-  override opaque type URI <: Node = rdfscala.URI
+  override opaque type rNode <: Matchable = rdfscala.TstNode
+  override opaque type rURI <: rNode  = rdfscala.URI
+  override opaque type Node <: rNode = rdfscala.TstNode
+  override opaque type URI <: Node & rURI = rdfscala.URI
 
   given rops: ROps[R] with
     override def mkUri(str: String): Try[RDF.URI[R]] = Try(