Low sitstart to the left of Physique Théorique (red n°13) with an undercling left hand and a small horizontal hold right hand and exit to the right of Physique Théorique (red n°13) without the right arete.
NB: often downgraded because of a much easier than 7c start without the first move (starting with the pocket left hand). A logical but harder start, directly nderneath the underclings, is also possible.