TEST(FactManagerTest, HandlesCorollariesWithInvalidIds) {
  std::string shader = R"(
               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %12 "main"
               OpExecutionMode %12 OriginUpperLeft
               OpSource ESSL 310
          %2 = OpTypeVoid
          %3 = OpTypeFunction %2
          %6 = OpTypeFloat 32
          %8 = OpTypeInt 32 1
          %9 = OpConstant %8 3
         %12 = OpFunction %2 None %3
         %13 = OpLabel
         %14 = OpConvertSToF %6 %9
         %15 = OpConvertSToF %6 %9
               OpReturn
               OpFunctionEnd
  )";

  const auto env = SPV_ENV_UNIVERSAL_1_3;
  const auto consumer = nullptr;
  const auto context = BuildModule(env, consumer, shader, kFuzzAssembleOption);
  ASSERT_TRUE(IsValid(env, context.get()));

  FactManager fact_manager;

  // Register %9 in the equivalence relation.
  fact_manager.AddFactDataSynonym(MakeDataDescriptor(9, {}),
                                  MakeDataDescriptor(9, {}), context.get());

  // Add an equation fact.
  fact_manager.AddFactIdEquation(14, SpvOpConvertSToF, {9}, context.get());

  // Remove the equation instruction from the module.
  ASSERT_TRUE(context->KillDef(14));

  // Add another equation.
  fact_manager.AddFactIdEquation(15, SpvOpConvertSToF, {9}, context.get());

  // The removed equation id (%14) and the new equation id (%15) should be
  // synonymous.
  ASSERT_TRUE(fact_manager.IsSynonymous(MakeDataDescriptor(14, {}),
                                        MakeDataDescriptor(15, {})));
}