diff --git a/Strata/Languages/Python/z3_configs.txt b/Strata/Languages/Python/z3_configs.txt
new file mode 100644
index 000000000..ab7b6a429
--- /dev/null
+++ b/Strata/Languages/Python/z3_configs.txt
@@ -0,0 +1,2 @@
+  
+(set-option :smt.mbqi false) (set-option :auto_config false)
diff --git a/Strata/Languages/Python/z3_parallel.py b/Strata/Languages/Python/z3_parallel.py
new file mode 100755
index 000000000..5b28d01df
--- /dev/null
+++ b/Strata/Languages/Python/z3_parallel.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+
+# Copyright Strata Contributors
+
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+# This file runs several configurations of Z3 in parallel, and returns SAT/UNSAT if
+# any return the same, only returning unknown if all return unknown / timeout.
+# Configurations can be added to z3_configs.txt, one per line.
+# The solvers currently run in parallel until completion. This could be improved, but
+# we currently use a 1s timeout, so it's not a high priority.
+
+import sys
+import subprocess
+import tempfile
+from pathlib import Path
+from concurrent.futures import ProcessPoolExecutor, as_completed
+
+def run_z3_config(smt_content, config_pair, timeout):
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.smt2', delete=False) as f:
+        f.write(f"{config_pair[0]} {config_pair[1]}\n")
+        f.write(smt_content)
+        f.flush()
+        
+        process = None
+        try:
+            process = subprocess.Popen(
+                ['z3', f'-T:{timeout}', f.name],
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                text=True
+            )
+            stdout, stderr = process.communicate(timeout=timeout)
+            Path(f.name).unlink()
+            
+            output = stdout.strip()
+            first_line = output.split('\n')[0].lower() if output else ''
+            if first_line == 'sat':
+                return 'sat', output
+            elif first_line == 'unsat':
+                return 'unsat', output
+            return None, output
+        except subprocess.TimeoutExpired:
+            if process:
+                process.kill()
+                process.wait()
+            Path(f.name).unlink()
+            return None, "timeout"
+        except Exception as e:
+            Path(f.name).unlink()
+            return None, str(e)
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: z3_parallel.py [-v] [-c config_file] <smt_file>")
+        sys.exit(1)
+    
+    verbose = False
+    config_file = None
+    args = sys.argv[1:]
+    
+    while args and args[0].startswith('-'):
+        if args[0] == '-v':
+            verbose = True
+            args = args[1:]
+        elif args[0] == '-c':
+            if len(args) < 2:
+                print("Usage: z3_parallel.py [-v] [-c config_file] <smt_file>")
+                sys.exit(1)
+            config_file = args[1]
+            args = args[2:]
+        else:
+            break
+    
+    if len(args) != 1:
+        print("Usage: z3_parallel.py [-v] [-c config_file] <smt_file>")
+        sys.exit(1)
+    
+    smt_file = args[0]
+    
+    if config_file is None:
+        script_dir = Path(__file__).parent
+        config_file = script_dir / 'z3_configs.txt'
+    
+    timeout = 1
+    
+    configs = []
+    with open(config_file) as f:
+        for line in f:
+            line = line.strip()
+            parts = line.split(maxsplit=1)
+            if len(parts) == 2:
+                configs.append(parts)
+            elif len(parts) == 0:
+                configs.append(('', ''))
+            else:
+                configs.append((parts[0], ''))
+    
+    with open(smt_file) as f:
+        smt_content = f.read()
+    
+    with ProcessPoolExecutor(max_workers=len(configs)) as executor:
+        futures = [executor.submit(run_z3_config, smt_content, cfg, timeout) for cfg in configs]
+        
+        sat_result = None
+        all_results = []
+        for future in as_completed(futures):
+            result, output = future.result()
+            all_results.append((result, output))
+            if result and not sat_result:
+                sat_result = (result, output)
+        
+        if verbose:
+            for i, (result, output) in enumerate(all_results):
+                print(f"Config {i}: {result or 'unknown'} - {output}")
+        
+        if sat_result:
+            print(sat_result[0])
+            return
+
+    print("unknown")
+
+if __name__ == '__main__':
+    main()
diff --git a/StrataMain.lean b/StrataMain.lean
index 5751dea67..dc4eae86e 100644
--- a/StrataMain.lean
+++ b/StrataMain.lean
@@ -205,10 +205,9 @@ def pyAnalyzeCommand : Command where
     if verbose then
       IO.println "Inlined: "
       IO.print newPgm
+    let solverName : String := "Strata/Languages/Python/z3_parallel.py"
     let vcResults ← EIO.toIO (fun f => IO.Error.userError (toString f))
-                        (Boogie.verify "z3" newPgm { Options.default with stopOnFirstError := false,
-                                                                          verbose,
-                                                                          removeIrrelevantAxioms := true }
+                        (Boogie.verify solverName newPgm { Options.default with stopOnFirstError := false, verbose, removeIrrelevantAxioms := true }
                                                    (moreFns := Strata.Python.ReFactory))
     let mut s := ""
     for vcResult in vcResults do
diff --git a/StrataTest/Languages/Python/expected/test_datetime.expected b/StrataTest/Languages/Python/expected/test_datetime.expected
index 9ca7ad8bf..032651103 100644
--- a/StrataTest/Languages/Python/expected/test_datetime.expected
+++ b/StrataTest/Languages/Python/expected/test_datetime.expected
@@ -15,8 +15,9 @@ ensures_maybe_except_none: verified
 
 py_assertion: unknown
 
-py_assertion: unknown
+py_assertion: verified
 
-py_assertion: unknown
+py_assertion: verified
 
-py_assertion: unknown
+py_assertion: failed
+CEx: 
diff --git a/StrataTest/Languages/Python/expected/test_function_def_calls.expected b/StrataTest/Languages/Python/expected/test_function_def_calls.expected
index ebb5e87f9..929ca1a80 100644
--- a/StrataTest/Languages/Python/expected/test_function_def_calls.expected
+++ b/StrataTest/Languages/Python/expected/test_function_def_calls.expected
@@ -14,7 +14,7 @@ assert_opt_name_none_or_bar: verified
 ensures_maybe_except_none: verified
 
 test_helper_procedure_assert_name_is_foo_3: failed
-CEx: ($__s49, "")
+CEx: 
 
 test_helper_procedure_assert_opt_name_none_or_str_4: verified