Fusion implementation of the model at http://yetanothermathprogrammingconsultant.blogspot.dk/2016/02/two-nonlinear-formulations.html

oven1.py

def oven1(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() )
    s = m.variable('s', n, Domain.unbounded() ) 
    d = m.variable('d', n, Domain.unbounded() ) 
    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.add( s, Expr.mulElm( M, y) ), Domain.lessThan(M) )
    m.constraint( Expr.sub( Expr.mulElm( M, y), s ), Domain.lessThan(M) )

    m.constraint( Expr.sub( Expr.add(d,x), s), Domain.equalsTo( A) )

    m.constraint( Expr.vstack( 0.5, t, Expr.mulElm( d, AS) ), Domain.inRotatedQCone() )
        
    m.objective( ObjectiveSense.Minimize, t)
        
    m.setLogHandler(sys.stdout)
    m.solve()

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