diff --git a/test/test_rearrange_einops.py b/test/test_rearrange_einops.py
index f2651fb6..faf159b9 100644
--- a/test/test_rearrange_einops.py
+++ b/test/test_rearrange_einops.py
@@ -61,6 +61,14 @@ class test_rearrange_examples(unittest.TestCase):
     y = y.rearrange("b c -> c b () ()")
     assert tuple(y.shape) == (20, 10, 1, 1)
 
+  def test9(self):
+    x = Tensor(np.arange(10 * 20 * 1 * 1).reshape([10, 20, 1, 1]))
+    # squeeze - unsqueeze
+    y = x.rearrange("b c 1 1 -> b c")
+    assert tuple(y.shape) == (10, 20)
+    y = y.rearrange("b1 c -> c b1 1 1")
+    assert tuple(y.shape) == (20, 10, 1, 1)
+
   def test_tensor_train_example_numpy(self):
     # kept here just for a collection, only tested for numpy
     # https://arxiv.org/pdf/1509.06569.pdf, (5)
@@ -131,6 +139,9 @@ class test_rearrange_ops(unittest.TestCase):
     with self.assertRaises(AssertionError):
       ## incorrect dimension provided for an axis that is only permuted
       y.rearrange("(a1 a2 a3) b -> b a3 a2 a1", a1=2, a2=2, b=2)
+    with self.assertRaises(AssertionError):
+      ## unused axis provided
+      y.rearrange("(a b c) d -> a b c d", b=2, c=2, e=2)
 
   def test_rearrange_ellipsis_ops(self):
     identity_patterns = [
diff --git a/tinygrad/tensor.py b/tinygrad/tensor.py
index 90d633e6..207903cb 100644
--- a/tinygrad/tensor.py
+++ b/tinygrad/tensor.py
@@ -1657,15 +1657,17 @@ class Tensor:
     ```
     """
     def parse_formula(formula: str):
-      lparens, rparens = map(lambda x: [i for i, ch in enumerate(formula.split()) if ch == x], ("(", ")"))
+      tokens = f" {formula} ".replace("…", "...").replace("(", " ( ").replace(")", " ) ").replace(" ", "  ").replace(" 1 ", " ( ) ").split()
+      lparens, rparens = map(lambda x: [i for i, ch in enumerate(tokens) if ch == x], ("(", ")"))
       pairs = list(zip(lparens, rparens))
       assert len(lparens) == len(rparens) and sorted(flatten(pairs)) == flatten(pairs), "bracket mismatch"
-      return [name for name in formula.split() if name not in ("(", ")")], [(s - 2*i, e - 1 - 2*i) for i, (s, e) in enumerate(pairs)]
+      return [name for name in tokens if name not in ("(", ")")], [(s - 2*i, e - 1 - 2*i) for i, (s, e) in enumerate(pairs)]
 
     assert formula.count("->") == 1, 'need exactly one "->" in formula'
 
-    (lhs, unflatten_dims), (rhs, flatten_dims) = map(parse_formula, formula.replace("…", "...").replace("(", " ( ").replace(")", " ) ").split("->"))
+    (lhs, unflatten_dims), (rhs, flatten_dims) = map(parse_formula, formula.split("->"))
 
+    for name in sizes: assert name in lhs, f"axis {name} is not used in transform"
     assert sorted(lhs) == sorted(rhs) and len(lhs) == len(set(lhs)), f"name mismatch in {formula}"
     for name in flatten((lhs, rhs)): assert name == "..." or (name.isidentifier() and "_" not in (name[0], name[-1])), f"invalid axis name {name}"
     assert "..." not in flatten([lhs[s:e] for s, e in unflatten_dims]), f"cannot have collapsed ellipsis (...) in lhs of {formula}"