High expansion backup, seal, and system

A backup including a resister articulated to a mounting ring, a support articulated to a support ring and the resister, the resister moving upon one of the mounting ring and the support ring moving away from the other. A seal including a mandrel, an element and a backup disposed on the mandrel adjacent the element. A borehole system including a borehole in a formation, a string in the borehole, a backup disposed within or as a part of the string. A backup including a deformable ring, a resister disposed adjacent the deformable ring, the resister being articulated to a ring mount through a pivot pin having a frustoconical geometry. A backup including a resister articulated to a ring, the resister including a borehole wall engager. A borehole system including a borehole in a subsurface formation, a string in the borehole, a backup within or as a part of the string.