// Test: Product Codomain Support
//
// This tests the new feature where functions can have product codomains,
// allowing record literal assignments like:
//   elem func = [field1: v1, field2: v2];

theory ProductCodomainTest {
  A : Sort;
  B : Sort;
  C : Sort;

  // Function with product codomain: maps A elements to (B, C) pairs
  pair_of : A -> [left: B, right: C];
}

instance TestInstance : ProductCodomainTest = {
  // Elements
  a1 : A;
  b1 : B;
  b2 : B;
  c1 : C;

  // Assign product codomain value using record literal
  a1 pair_of = [left: b1, right: c1];
}

// A more realistic example: Edges in a graph
theory DirectedGraph {
  V : Sort;
  E : Sort;

  // Edge endpoints as a product codomain
  endpoints : E -> [src: V, tgt: V];
}

instance TriangleGraph : DirectedGraph = {
  // Vertices
  v0 : V;
  v1 : V;
  v2 : V;

  // Edges
  e01 : E;
  e12 : E;
  e20 : E;

  // Assign edge endpoints using record literals
  e01 endpoints = [src: v0, tgt: v1];
  e12 endpoints = [src: v1, tgt: v2];
  e20 endpoints = [src: v2, tgt: v0];
}