diff --git a/crosshair/copyext_test.py b/crosshair/copyext_test.py
index 8bc80ff8..1aec0e2d 100644
--- a/crosshair/copyext_test.py
+++ b/crosshair/copyext_test.py
@@ -33,19 +33,17 @@ def test_deepcopyext_symbolic_set():
             deepcopyext(s, CopyMode.REALIZE, {})
 
 
-def test_deepcopyext_realize():
-    with standalone_statespace, NoTracing():
-        x = SymbolicInt("x")
-        lock = RLock()
-        lockarray = [lock]
-        input = {"a": ([x], lockarray, lockarray)}
+def test_deepcopyext_realize(space):
+    x = SymbolicInt("x")
+    lock = RLock()
+    lockarray = [lock]
+    input = {"a": ([x], lockarray, lockarray)}
     output = deepcopyext(input, CopyMode.REALIZE, {})
-    with NoTracing():
-        assert input is not output
-        assert input["a"] is not output["a"]
-        assert output["a"][1] is output["a"][2]  # memo preserves identity
-        assert type(input["a"][0][0]) is SymbolicInt
-        assert type(output["a"][0][0]) is int
+    assert input is not output
+    assert input["a"] is not output["a"]
+    assert output["a"][1] is output["a"][2]  # memo preserves identity
+    assert type(input["a"][0][0]) is SymbolicInt
+    assert type(output["a"][0][0]) is int
 
 
 def test_deepcopyext_tuple_type():
diff --git a/crosshair/core_test.py b/crosshair/core_test.py
index f7ca8ea1..82003e97 100644
--- a/crosshair/core_test.py
+++ b/crosshair/core_test.py
@@ -1220,10 +1220,9 @@ def dothing(foo: WithUnpickleableArg) -> int:
 
 
 @pytest.mark.smoke
-def test_deep_realize():
-    with standalone_statespace as space:
-        x = proxy_for_type(int, "x")
-        space.add(x.var == 4)
+def test_deep_realize(space):
+    x = proxy_for_type(int, "x")
+    space.add(x.var == 4)
 
     @dataclasses.dataclass
     class Woo:
diff --git a/crosshair/libimpl/builtinslib.py b/crosshair/libimpl/builtinslib.py
index 5d6ff438..a8dcd419 100644
--- a/crosshair/libimpl/builtinslib.py
+++ b/crosshair/libimpl/builtinslib.py
@@ -250,7 +250,6 @@ class SymbolicValue(CrossHairValue):
     def __init__(self, smtvar: Union[str, z3.ExprRef], typ: Type):
         if is_tracing():
             raise CrosshairInternal
-        self.statespace = context_statespace()
         self.snapshot = SnapshotRef(-1)
         self.python_type = typ
         if type(smtvar) is str:
@@ -264,7 +263,7 @@ def __init_var__(self, typ, varname):
 
     def __deepcopy__(self, memo):
         result = copy.copy(self)
-        result.snapshot = self.statespace.current_snapshot()
+        result.snapshot = context_statespace().current_snapshot()
         memo[id(self)] = result
         return result
 
@@ -1007,7 +1006,7 @@ def _smt_promote_literal(cls, literal) -> Optional[z3.SortRef]:
 
     def __ch_realize__(self) -> object:
         with NoTracing():
-            return self.statespace.choose_possible(self.var)
+            return context_statespace().choose_possible(self.var)
 
     def __neg__(self):
         with NoTracing():
@@ -1025,7 +1024,7 @@ def __index__(self):
 
     def __bool__(self):
         with NoTracing():
-            return self.statespace.choose_possible(self.var)
+            return context_statespace().choose_possible(self.var)
 
     def __int__(self):
         with NoTracing():
@@ -1068,7 +1067,7 @@ def from_bytes(cls, b: bytes, byteorder: str, signed=False) -> int:
         return int.from_bytes(b, byteorder, signed=signed)  # type: ignore
 
     def __ch_realize__(self) -> object:
-        return self.statespace.find_model_value(self.var)
+        return context_statespace().find_model_value(self.var)
 
     def __repr__(self):
         if self < 0:
@@ -1236,13 +1235,13 @@ def _smt_promote_literal(cls, literal) -> Optional[z3.SortRef]:
         return None
 
     def __ch_realize__(self) -> object:
-        return self.statespace.find_model_value(self.var).__float__()  # type: ignore
+        return context_statespace().find_model_value(self.var).__float__()  # type: ignore
 
     def __repr__(self):
-        return self.statespace.find_model_value(self.var).__repr__()
+        return context_statespace().find_model_value(self.var).__repr__()
 
     def __hash__(self):
-        return self.statespace.find_model_value(self.var).__hash__()
+        return context_statespace().find_model_value(self.var).__hash__()
 
     def __bool__(self):
         with NoTracing():
@@ -1344,7 +1343,7 @@ def __init__(self, smtvar: Union[str, z3.ExprRef], typ: Type):
             self.ch_key_type = None
             self.smt_key_sort = HeapRef
         SymbolicValue.__init__(self, smtvar, typ)
-        self.statespace.add(self._len() >= 0)
+        context_statespace().add(self._len() >= 0)
 
     def __ch_realize__(self):
         return origin_of(self.python_type)(self)
@@ -1402,9 +1401,10 @@ def __init_var__(self, typ, varname):
         arr_smt_sort = z3.ArraySort(
             self.smt_key_sort, possibly_missing_sort(self.smt_val_sort)
         )
+        space = context_statespace()
         return (
-            z3.Const(varname + "_map" + self.statespace.uniq(), arr_smt_sort),
-            z3.Const(varname + "_len" + self.statespace.uniq(), _SMT_INT_SORT),
+            z3.Const(varname + "_map" + space.uniq(), arr_smt_sort),
+            z3.Const(varname + "_len" + space.uniq(), _SMT_INT_SORT),
         )
 
     def __eq__(self, other):
@@ -1455,7 +1455,7 @@ def __getitem__(self, k):
             if SymbolicBool(self._len() == 0).__bool__():
                 raise IgnoreAttempt("SymbolicDict in inconsistent state")
             return smt_to_ch_value(
-                self.statespace,
+                context_statespace(),
                 self.snapshot,
                 self.val_accessor(possibly_missing),
                 self.val_pytype,
@@ -1468,7 +1468,7 @@ def __iter__(self):
         with NoTracing():
             arr_var, len_var = self.var
             iter_cache = self._iter_cache
-            space = self.statespace
+            space = context_statespace()
             idx = 0
             arr_sort = self._arr().sort()
             is_missing = self.val_missing_checker
@@ -1509,7 +1509,7 @@ def __init__(self, smtvar: Union[str, z3.ExprRef], typ: Type):
         SymbolicDictOrSet.__init__(self, smtvar, typ)
         self._iter_cache: List[z3.Const] = []
         self.empty = z3.K(self._arr().sort().domain(), False)
-        self.statespace.add((self._arr() == self.empty) == (self._len() == 0))
+        context_statespace().add((self._arr() == self.empty) == (self._len() == 0))
 
     def __ch_realize__(self):
         return python_type(self)(map(realize, self))
@@ -1543,12 +1543,13 @@ def __eq__(self, other):
 
     def __init_var__(self, typ, varname):
         assert typ == self.python_type
+        space = context_statespace()
         return (
             z3.Const(
-                varname + "_map" + self.statespace.uniq(),
+                varname + "_map" + space.uniq(),
                 z3.ArraySort(self.smt_key_sort, _SMT_BOOL_SORT),
             ),
-            z3.Const(varname + "_len" + self.statespace.uniq(), _SMT_INT_SORT),
+            z3.Const(varname + "_len" + space.uniq(), _SMT_INT_SORT),
         )
 
     def __contains__(self, key):
@@ -1572,7 +1573,7 @@ def __iter__(self):
         with NoTracing():
             arr_var, len_var = self.var
             iter_cache = self._iter_cache
-            space = self.statespace
+            space = context_statespace()
             idx = 0
             arr_sort = self._arr().sort()
             keys_on_heap = is_heapref_sort(arr_sort.domain())
@@ -1611,9 +1612,7 @@ def __iter__(self):
                 arr_var = remaining
             # In this conditional, we reconcile the parallel symbolic variables for length
             # and contents:
-            if self.statespace.choose_possible(
-                arr_var != self.empty, probability_true=0.0
-            ):
+            if space.choose_possible(arr_var != self.empty, probability_true=0.0):
                 raise IgnoreAttempt("SymbolicSet in inconsistent state")
 
     def _set_op(self, attr, other):
@@ -1799,14 +1798,15 @@ def __init__(self, smtvar: Union[str, z3.ExprRef], typ: Any):
 
         SymbolicValue.__init__(self, smtvar, typ)
         len_var = self._len()
-        self.statespace.add(len_var >= 0)
+        context_statespace().add(len_var >= 0)
 
     def __init_var__(self, typ, varname):
         assert typ == self.python_type
         arr_smt_type = z3.ArraySort(_SMT_INT_SORT, self.item_smt_sort)
+        space = context_statespace()
         return (
-            z3.Const(varname + "_map" + self.statespace.uniq(), arr_smt_type),
-            z3.Const(varname + "_len" + self.statespace.uniq(), _SMT_INT_SORT),
+            z3.Const(varname + "_map" + space.uniq(), arr_smt_type),
+            z3.Const(varname + "_len" + space.uniq(), _SMT_INT_SORT),
         )
 
     def _arr(self):
@@ -1872,7 +1872,7 @@ def __radd__(self, other: object):
         return NotImplemented
 
     def __contains__(self, other):
-        space = self.statespace
+        space = context_statespace()
         with NoTracing():
             if not is_heapref_sort(self.item_smt_sort):
                 smt_other = self.ch_item_type._coerce_to_smt_sort(other)
@@ -1895,7 +1895,7 @@ def __contains__(self, other):
         return False
 
     def __getitem__(self, i):
-        space = self.statespace
+        space = context_statespace()
         with NoTracing():
             if (
                 isinstance(i, slice)
@@ -2127,7 +2127,7 @@ def _is_superclass_of_(self, other):
         if type(other) is SymbolicType:
             # Prefer it this way because only _is_subcless_of_ does the type cap lowering.
             return other._is_subclass_of_(self)
-        space = self.statespace
+        space = context_statespace()
         coerced = SymbolicType._coerce_to_smt_sort(other)
         if coerced is None:
             return False
@@ -2143,7 +2143,7 @@ def _is_subclass_of_(self, other):
         assert not is_tracing()
         if self is SymbolicType:
             return False
-        space = self.statespace
+        space = context_statespace()
         coerced = SymbolicType._coerce_to_smt_sort(other)
         if coerced is None:
             return False
@@ -2185,7 +2185,7 @@ def _realized(self):
     def _realize(self) -> Type:
         with NoTracing():
             cap = self.pytype_cap
-            space = self.statespace
+            space = context_statespace()
             type_repo = space.extra(SymbolicTypeRepository)
             if cap is object:
                 # We don't attempt every possible Python type! Just some basic ones.
@@ -3341,7 +3341,7 @@ def _smt_promote_literal(cls, literal) -> Optional[z3.SortRef]:
         return None
 
     def __ch_realize__(self) -> object:
-        codepoints = self.statespace.find_model_value(self.var)
+        codepoints = context_statespace().find_model_value(self.var)
         return "".join(chr(x) for x in codepoints)
 
     def __copy__(self):
@@ -3386,7 +3386,6 @@ def __radd__(self, other):
             raise TypeError
 
     def __mul__(self, other):
-        self.statespace
         if isinstance(other, Integral):
             if other <= 1:
                 return self if other == 1 else ""
@@ -3409,7 +3408,7 @@ def __contains__(self, other):
     def __getitem__(self, i: Union[int, slice]):
         with NoTracing():
             idx_or_pair = process_slice_vs_symbolic_len(
-                self.statespace, i, z3.Length(self.var)
+                context_statespace(), i, z3.Length(self.var)
             )
             if isinstance(idx_or_pair, tuple):
                 (start, stop) = idx_or_pair
@@ -3427,7 +3426,7 @@ def find(self, substr, start=None, end=None):
         if not isinstance(substr, str):
             raise TypeError
         with NoTracing():
-            space = self.statespace
+            space = context_statespace()
             smt_my_len = z3.Length(self.var)
             if start is None and end is None:
                 smt_start = z3IntVal(0)
@@ -3493,7 +3492,7 @@ def rfind(self, substr, start=None, end=None) -> Union[int, SymbolicInt]:
         if not isinstance(substr, str):
             raise TypeError
         with NoTracing():
-            space = self.statespace
+            space = context_statespace()
             smt_my_len = z3.Length(self.var)
             if start is None and end is None:
                 smt_start = z3IntVal(0)