diff --git a/typed-ontology-simple-meta/src/main/scala/ru/primetalk/typed/ontology/simple/meta/Projector.scala b/typed-ontology-simple-meta/src/main/scala/ru/primetalk/typed/ontology/simple/meta/Projector.scala
new file mode 100644
index 0000000..e386074
--- /dev/null
+++ b/typed-ontology-simple-meta/src/main/scala/ru/primetalk/typed/ontology/simple/meta/Projector.scala
@@ -0,0 +1,12 @@
+package ru.primetalk.typed.ontology.simple.meta
+
+trait Projector[From <: SchemaLike, To <: SchemaLike]:
+  val from: SchemaValueType.Aux1[From]
+  val to: SchemaValueType.Aux1[To]
+  def apply(v: from.Value): to.Value
+
+trait Concatenator[A <: RecordSchema, B <: RecordSchema]:
+  val aSvt: RecordSchemaValueType[A]
+  val bSvt: RecordSchemaValueType[B]
+  val abSvt: RecordSchemaValueType[RecordSchema.Concat[A, B]]
+  def apply(a: aSvt.Value, b: bSvt.Value): abSvt.Value