semantic-equivalence-verifier

To formally prove code equivalence after refactoring, use symbolic execution and SMT solvers to mathematically verify that two program fragments behave identically across all valid inputs, rather than relying solely on test suites.

Formal verification is needed instead of differential testing when input spaces are too large, adversarial, or when correctness must be formally guaranteed for safety-critical systems or regulatory compliance.

The best way to verify code correctness for large input spaces is using SMT-backed equivalence and symbolic reasoning to mathematically prove behavior preservation across all possible inputs.

Symbolic execution proves program behavior is preserved by reasoning about code semantics and using SMT solvers to check equivalence, employing strategies like induction and simulation relations.

Yes, you can prove equivalence for C code with specific preconditions, such as verifying an old fragment matches a new one under the condition that a variable is not a specific minimum value.

Limitations of using SMT solvers for formal verification include handling complex scenarios where differential testing is insufficient, requiring strategies like induction and simulation relations to manage large or adversarial input spaces.