@Override
  @NotNull
  default DfType meetRelation(@NotNull RelationType relationType,
                              @NotNull DfType other) {
    DfType result = meet(other.fromRelation(relationType));
    if (result == DfType.BOTTOM && relationType != RelationType.NE) {
      if (!isSuperType(DfTypes.DOUBLE_NAN) && other.isSuperType(DfTypes.DOUBLE_NAN)) {
        return this;
      }
    }
    return result;
  }
@Override
  @NotNull
  default DfType meetRelation(@NotNull RelationType relationType,
                              @NotNull DfType other)