code: package it.unibz.inf.ontop.model.term.functionsymbol.impl;
  
  import com.google.common.collect.ImmutableList;
  import it.unibz.inf.ontop.iq.node.VariableNullability;
  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.DBFunctionSymbol;
  import it.unibz.inf.ontop.model.type.DBTermType;
  import it.unibz.inf.ontop.model.type.RDFDatatype;
  import it.unibz.inf.ontop.model.type.RDFTermType;
  import it.unibz.inf.ontop.model.type.TermTypeInference;
  import org.apache.commons.rdf.api.IRI;
  
  import java.util.Optional;
  import java.util.function.Function;
  
  
  public class UnaryNumericSPARQLFunctionSymbolImpl extends ReduciblePositiveAritySPARQLFunctionSymbolImpl {
  
      private final Function<DBTermType, Optional<DBFunctionSymbol>> dbFunctionSymbolFct;
  
      protected UnaryNumericSPARQLFunctionSymbolImpl(String officialName,
                                                     RDFDatatype abstractNumericType,
                                                     Function<DBTermType, Optional<DBFunctionSymbol>> dbFunctionSymbolFct) {
          super("SP_" + officialName, officialName, ImmutableList.of(abstractNumericType));
          this.dbFunctionSymbolFct = dbFunctionSymbolFct;
      }
  
      protected UnaryNumericSPARQLFunctionSymbolImpl(String functionSymbolName, IRI functionIRI,
                                                     RDFDatatype abstractNumericType,
                                                     Function<DBTermType, Optional<DBFunctionSymbol>> dbFunctionSymbolFct) {
          super(functionSymbolName, functionIRI, ImmutableList.of(abstractNumericType));
          this.dbFunctionSymbolFct = dbFunctionSymbolFct;
      }
  
      /**
       * Makes sure sub-types of xsd:integer are replaced by xsd:integer
       */
      @Override
      protected ImmutableTerm computeTypeTerm(ImmutableList<? extends ImmutableTerm> subLexicalTerms,
                                              ImmutableList<ImmutableTerm> typeTerms, TermFactory termFactory,
                                              VariableNullability variableNullability) {
          ImmutableTerm typeTerm = typeTerms.get(0);
          return termFactory.getCommonPropagatedOrSubstitutedNumericType(typeTerm, typeTerm)
                  .simplify(variableNullability);
      }
  
      @Override
      protected ImmutableTerm computeLexicalTerm(ImmutableList<ImmutableTerm> subLexicalTerms,
                                                 ImmutableList<ImmutableTerm> typeTerms, TermFactory termFactory,
                                                 ImmutableTerm returnedRDFTypeTerm) {
          return termFactory.getUnaryLexicalFunctionalTerm(subLexicalTerms.get(0), returnedRDFTypeTerm,
                  dbFunctionSymbolFct);
      }
  
      @Override
      public boolean isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms() {
          return false;
      }
  
      /**
       * Too complex logic so not infer at this level (but after simplification into DB functional terms)
       */
      @Override
      public Optional<TermTypeInference> inferType(ImmutableList<? extends ImmutableTerm> terms) {
          return Optional.empty();
      }
  
      @Override
      public boolean canBePostProcessed(ImmutableList<? extends ImmutableTerm> arguments) {
          return false;
      }
  }
  