Compact model for the problem in http://yetanothermathprogrammingconsultant.blogspot.dk/2016/02/two-nonlinear-formulations.html

oven2.py

def oven2(N, M, A, T):

    AS = [ 1./math.sqrt(a) for a in A ]

    with Model() as m:

        x = m.variable('x', N, Domain.greaterThan(0.) )
        y = m.variable('y', N, Domain.inRange(0.,1.0), Domain.isInteger() )
        t = m.variable('t', 1, Domain.unbounded() )

        m.constraint( Expr.sum(x) , Domain.equalsTo(T) )

        m.constraint( Expr.sub( x, Expr.mulElm( M, y) ), Domain.lessThan(0.) )
    
        m.constraint( Expr.vstack( 0.5, t, Expr.mulElm(AS, Expr.sub(A,x)) ), Domain.inRotatedQCone() )

        m.objective( ObjectiveSense.Minimize, Expr.sub( t, Expr.dot( A, Expr.sub(1., y ) ) ) )
                                                     
        m.setLogHandler(sys.stdout)
        m.solve()

        return x.level(), y.level()