Method constructBilinearLayer

src/engine/InputQuery.cpp:1718–1823

}

bool InputQuery::constructBilinearLayer( NLR::NetworkLevelReasoner *nlr,
                                         Map<unsigned, unsigned> &handledVariableToLayer,
                                         unsigned newLayerIndex,
                                         Set<NonlinearConstraint *> &handledNLConstraints )
{
    INPUT_QUERY_LOG( "Attempting to construct BilinearLayer..." );
    struct NeuronInformation
    {
    public:
        NeuronInformation( unsigned variable,
                           unsigned neuron,
                           const Vector<unsigned> &sourceVariables )
            : _variable( variable )
            , _neuron( neuron )
            , _sourceVariables( sourceVariables )
        {
        }

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

    List<NeuronInformation> newNeurons;

    // Look for Bilinear constaints where all the element variables have already been handled
    const List<NonlinearConstraint *> &nlConstraints = getNonlinearConstraints();

    for ( const auto &nlc : nlConstraints )
    {
        if ( handledNLConstraints.exists( nlc ) )
            continue;

        // Only consider bilinear
        if ( nlc->getType() != BILINEAR )
            continue;

        const BilinearConstraint *bilinear = (const BilinearConstraint *)nlc;

        // Have all elements been handled?
        bool missingElement = false;
        for ( const auto &element : bilinear->getBs() )
        {
            if ( !handledVariableToLayer.exists( element ) )
            {
                missingElement = true;
                break;
            }
        }

        if ( missingElement )
            continue;

        // If the f variable has also been handled, ignore this constraint
        unsigned f = bilinear->getF();
        if ( handledVariableToLayer.exists( f ) )
            continue;