With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The current Doctor is the tenth.
text_B: The cylindrical grinder is a type of grinding machine used to shape the outside of an object .. grinding machine. grinding machine. The cylindrical grinder can work on a variety of shapes , however the object must have a central axis of rotation .. This includes but is not limited to such shapes as a cylinder , an ellipse , a cam , or a crankshaft .. cylinder. Cylinder ( geometry ). ellipse. ellipse. cam. cam. crankshaft. crankshaft. Cylindrical grinding is defined as having four essential actions  :. The work -LRB- object -RRB- must be constantly rotating. The grinding wheel must be constantly rotating. The grinding wheel is fed towards and away from the work. Either the work or the grinding wheel is traversed with respect to the other .. While the majority of cylindrical grinders employ all four movements , there are grinders that only employ three of the four actions .
not_related.