Method encodeBilinearConstraint

src/engine/MILPEncoder.cpp:692–729

}

void MILPEncoder::encodeBilinearConstraint( GurobiWrapper &gurobi,
                                            BilinearConstraint *bilinear,
                                            bool relax )
{
    if ( relax )
    {
        // Encode the DeepPoly abstraction
        auto sourceVariables = bilinear->getBs();
        unsigned sourceVariable1 = sourceVariables[0];
        unsigned sourceVariable2 = sourceVariables[1];
        unsigned targetVariable = bilinear->getF();
        double sourceLb1 = _tableau.getLowerBound( sourceVariable1 );
        double sourceLb2 = _tableau.getLowerBound( sourceVariable2 );
        double sourceUb2 = _tableau.getUpperBound( sourceVariable2 );

        List<GurobiWrapper::Term> terms;
        terms.append( GurobiWrapper::Term( 1, Stringf( "x%u", targetVariable ) ) );
        terms.append( GurobiWrapper::Term( -sourceLb2, Stringf( "x%u", sourceVariable1 ) ) );
        terms.append( GurobiWrapper::Term( -sourceLb1, Stringf( "x%u", sourceVariable2 ) ) );
        gurobi.addGeqConstraint( terms, -sourceLb1 * sourceLb2 );

        terms.clear();
        terms.append( GurobiWrapper::Term( 1, Stringf( "x%u", targetVariable ) ) );
        terms.append( GurobiWrapper::Term( -sourceUb2, Stringf( "x%u", sourceVariable1 ) ) );
        terms.append( GurobiWrapper::Term( -sourceLb1, Stringf( "x%u", sourceVariable2 ) ) );
        gurobi.addLeqConstraint( terms, -sourceLb1 * sourceUb2 );
    }
    else
    {
        gurobi.nonConvex();
        auto bs = bilinear->getBs();
        ASSERT( bs.size() == 2 );
        auto f = bilinear->getF();
        gurobi.addBilinearConstraint(
            Stringf( "x%u", bs[0] ), Stringf( "x%u", bs[1] ), Stringf( "x%u", f ) );
        return;
    }
}

void MILPEncoder::encodeRoundConstraint( GurobiWrapper &gurobi, RoundConstraint *round, bool relax )
{