code: package it.unibz.inf.ontop.model.term.functionsymbol.db.impl;
  
  import com.google.common.collect.ImmutableList;
  import it.unibz.inf.ontop.model.term.ImmutableTerm;
  import it.unibz.inf.ontop.model.term.TermFactory;
  import it.unibz.inf.ontop.model.term.functionsymbol.db.DBMathBinaryOperator;
  import it.unibz.inf.ontop.model.term.functionsymbol.impl.FunctionSymbolImpl;
  import it.unibz.inf.ontop.model.type.DBTermType;
  import it.unibz.inf.ontop.model.type.TermTypeInference;
  
  import java.util.Optional;
  import java.util.function.Function;
  
  /**
   * Mostly for the native query parser (for source queries in the mapping),
   * which is not able to infer the type of its input.
   *
   * Ideally, these operators should be replaced by typed ones later on in the mapping process, once the input type
   * can be inferred.
   *
   */
  public class DefaultUntypedDBMathBinaryOperator extends FunctionSymbolImpl implements DBMathBinaryOperator {
  
      private final String template;
  
      protected DefaultUntypedDBMathBinaryOperator(String operatorString, DBTermType rootDBTermType) {
          super("UNTYPED" + operatorString, ImmutableList.of(rootDBTermType, rootDBTermType));
          this.template = "(%s " + operatorString + " %s)";
      }
  
      @Override
      public String getNativeDBString(ImmutableList<? extends ImmutableTerm> terms,
                                      Function<ImmutableTerm, String> termConverter, TermFactory termFactory) {
          return String.format(template, termConverter.apply(terms.get(0)), termConverter.apply(terms.get(1)));
      }
  
      @Override
      protected boolean tolerateNulls() {
          return false;
      }
  
      @Override
      protected boolean mayReturnNullWithoutNullArguments() {
          return false;
      }
  
      @Override
      public boolean isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms() {
          return false;
      }
  
      @Override
      public Optional<TermTypeInference> inferType(ImmutableList<? extends ImmutableTerm> terms) {
          return Optional.empty();
      }
  
      @Override
      public boolean canBePostProcessed(ImmutableList<? extends ImmutableTerm> arguments) {
          return false;
      }
  
      /**
       * By default, to be overridden when necessary
       */
      @Override
      public boolean isPreferringToBePostProcessedOverBeingBlocked() {
          return false;
      }
  }
  