code: package it.unibz.inf.ontop.model.term.impl;
  
  import com.google.common.collect.ImmutableSet;
  import it.unibz.inf.ontop.iq.node.VariableNullability;
  import it.unibz.inf.ontop.model.term.IncrementalEvaluation;
  import it.unibz.inf.ontop.model.term.Variable;
  
  public abstract class AbstractNonNullConstant extends AbstractNonFunctionalTerm {
  
      @Override
      public IncrementalEvaluation evaluateIsNotNull(VariableNullability variableNullability) {
          return IncrementalEvaluation.declareIsTrue();
      }
  
      @Override
      public boolean isNullable(ImmutableSet<Variable> nullableVariables) {
          return false;
      }
  }
  