test: injection tactic tests

tests/lean/run/inj1.lean

@@ -0,0 +1,36 @@
+new_frontend
+
+theorem test1 {α} (a b : α) (as bs : List α) (h : a::as = b::bs) : a = b :=
+begin
+  injection h;
+  assumption;
+end
+
+theorem test2 {α} (a b : α) (as bs : List α) (h : a::as = b::bs) : a = b :=
+begin
+  injection h with h1 h2;
+  exact h1
+end
+
+theorem test3 {α} (a b : α) (as bs : List α) (h : (x : List α) → (y : List α) → x = y) : as = bs :=
+have a::as = b::bs from h (a::as) (b::bs);
+begin
+  injection this with h1 h2;
+  exact h2
+end
+
+theorem test4 {α} (a b : α) (as bs : List α) (h : (x : List α) → (y : List α) → x = y) : as = bs :=
+begin
+  injection h (a::as) (b::bs) with h1 h2;
+  exact h2
+end
+
+theorem test5 {α} (a : α) (as : List α) (h : a::as = []) : 0 > 1 :=
+begin
+  injection h
+end
+
+theorem test6 (n : Nat) (h : n+1 = 0) : 0 > 1 :=
+begin
+  injection h
+end