arrowhead identification

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2021-01-19-231103-293d902-018486#ico_minus">