test(tests/lean/run/match_expr2): match example with abstract structures

tests/lean/run/match_expr2.lean

@@ -0,0 +1,13 @@
+import algebra.ordered_ring
+open tactic
+axiom Sorry : ∀ {A:Type}, A
+
+example {A : Type} [ordered_ring A] (a b c : A) (h₀ : c > 0) (h₁ : a > 1) (h₂ : b > 0) : a + b + c = 0 :=
+by do
+  [x, y] ← match_target_subexpr `(λ x y : A, x + y) | failed,
+  trace "------ subterms -------",
+  trace x, trace y,
+  (h, [z]) ← match_hypothesis `(λ x : A, x > 1) | failed,
+  trace "--- hypothesis of the form x > 1 ---",
+  trace h, trace z,
+  refine `(Sorry)