\starttext

    \setupinteraction[state=start]
    \placeregister[index]

    \page

    test \index{aindex}test \page
    test \index{aindex}test \page

    test \seeindex{aindex}{bindex}text \page
    test \seeindex{bindex}{aindex}text \page

    test \index{bindex}text \page
    test \index{bindex}text \page

    test \seeindex{cindex}{bindex}text \page
    test \seeindex{cindex}{aindex}text

\stoptext
