code: package it.unibz.inf.ontop.model.term.functionsymbol.db.impl;
  
  import com.google.common.collect.ImmutableList;
  import it.unibz.inf.ontop.iq.node.VariableNullability;
  import it.unibz.inf.ontop.model.term.*;
  import it.unibz.inf.ontop.model.term.functionsymbol.db.DBFunctionSymbolSerializer;
  import it.unibz.inf.ontop.model.type.DBTermType;
  
  import java.util.function.Function;
  
  public class DBContainsFunctionSymbolImpl extends DBBooleanFunctionSymbolImpl {
  
      private final DBFunctionSymbolSerializer serializer;
  
      protected DBContainsFunctionSymbolImpl(DBTermType abstractRootTermType, DBTermType dbBooleanTermType,
                                             DBFunctionSymbolSerializer serializer) {
          super("DB_CONTAINS",
                  ImmutableList.of(abstractRootTermType, abstractRootTermType),
                  dbBooleanTermType);
          this.serializer = serializer;
      }
  
      @Override
      public boolean blocksNegation() {
          return true;
      }
  
      @Override
      public ImmutableExpression negate(ImmutableList<? extends ImmutableTerm> subTerms, TermFactory termFactory) {
          throw new UnsupportedOperationException();
      }
  
      @Override
      public boolean isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms() {
          return false;
      }
  
      @Override
      public boolean canBePostProcessed(ImmutableList<? extends ImmutableTerm> arguments) {
          return true;
      }
  
      @Override
      public String getNativeDBString(ImmutableList<? extends ImmutableTerm> terms,
                                      Function<ImmutableTerm, String> termConverter,
                                      TermFactory termFactory) {
          return serializer.getNativeDBString(terms, termConverter, termFactory);
      }
  
      @Override
      protected boolean tolerateNulls() {
          return false;
      }
  
      @Override
      protected ImmutableTerm buildTermAfterEvaluation(ImmutableList<ImmutableTerm> newTerms, TermFactory termFactory,
                                                       VariableNullability variableNullability) {
          if (newTerms.stream().allMatch(t -> t instanceof DBConstant)) {
              String mainString = ((DBConstant) newTerms.get(0)).getValue();
              String searchString = ((DBConstant) newTerms.get(1)).getValue();
  
              return termFactory.getDBBooleanConstant(mainString.contains(searchString));
          }
  
          return super.buildTermAfterEvaluation(newTerms, termFactory, variableNullability);
      }
  }
  