You may not notice some of the works in Gordon Hall’s first solo show; the entry walls are partly painted in delicate pastel off-whites, and while the gesture may seem precious, it indicates the artist’s admirable ambitions toward subtlety. The show’s palindromic title, “Never Odd or Even,” suggests a slipperiness of categorization. Double (I), for example, pairs an old wooden stool that the artist found at a residency with a shiny, brand-new replica. Does either of them, one might ask, embody stool-ness more than the other? Look for the artist, who also founded the Center for Experimental Lectures, in the upcoming “Crossing Brooklyn” show at the Brooklyn Museum.