test(tests/lean/run): add structure instance example

tests/lean/run/struct_inst_exprs2.lean

@@ -0,0 +1,20 @@
+import data.nat.basic
+open nat
+
+structure s1 (A : Type) :=
+(x : A) (y : A) (h : x = y)
+
+structure s2 (A : Type) :=
+(mul : A → A → A) (one : A)
+
+structure s3 (A : Type) extends s1 A, s2 A :=
+(mul_one : ∀ a : A, mul a one = a)
+
+definition v1 : s1 nat := {| s1, x := 10, y := 10, h := rfl |}
+definition v2 : s2 nat := {| s2, mul := nat.add, one := zero |}
+definition v3 : s3 nat := {| s3, mul_one := add_zero, using v1, using v2 |}
+
+example : s3.x v3 = 10 := rfl
+example : s3.y v3 = 10 := rfl
+example : s3.mul v3 = nat.add  := rfl
+example : s3.one v3 = nat.zero := rfl