Method constructMaxLayer

src/engine/InputQuery.cpp:1600–1716

}

bool InputQuery::constructMaxLayer( NLR::NetworkLevelReasoner *nlr,
                                    Map<unsigned, unsigned> &handledVariableToLayer,
                                    unsigned newLayerIndex,
                                    Set<PiecewiseLinearConstraint *> &handledPLConstraints )
{
    INPUT_QUERY_LOG( "Attempting to construct MaxLayer..." );
    struct NeuronInformation
    {
    public:
        NeuronInformation( unsigned variable,
                           unsigned neuron,
                           const List<unsigned> &sourceVariables )
            : _variable( variable )
            , _neuron( neuron )
            , _sourceVariables( sourceVariables )
        {
        }

        unsigned _variable;
        unsigned _neuron;
        List<unsigned> _sourceVariables;
    };

    List<NeuronInformation> newNeurons;

    // Look for Maxes where all the element variables have already been handled
    const List<PiecewiseLinearConstraint *> &plConstraints = getPiecewiseLinearConstraints();

    unsigned currentSourceLayer = 0;
    for ( const auto &plc : plConstraints )
    {
        if ( handledPLConstraints.exists( plc ) )
            continue;

        // Only consider Max
        if ( plc->getType() != MAX )
            continue;

        const MaxConstraint *max = (const MaxConstraint *)plc;

        // Have all elements been handled?
        // Have all input variables been handled?
        bool missingInput = false;
        bool sourceLayerDiffers = false;
        for ( const auto &input : max->getElements() )
        {
            if ( !handledVariableToLayer.exists( input ) )
            {
                missingInput = true;
                break;
            }
            else if ( _ensureSameSourceLayerInNLR && newNeurons.size() &&
                      handledVariableToLayer[input] != currentSourceLayer )
            {
                sourceLayerDiffers = true;
                break;
            }
        }