“The Constant Possibility of Erasure” through Jan. 29. Organized by Donna Harkavy and Gracie Mansion, this excellent group show is at once witty and elegiac, exploring transience as an existential reality and as a conceptual ploy in late 20th century art. Robert Rauschenberg’s 1953 “Erased De Kooning” is an important reference point, present through Mike Bidlo’s painstaking recreation. Joseph Beuys, Gary Simmons and Christian Xarcc all have chalk pieces on blackboards, while Allan Kaprow preferred drawing, and simultaneously erasing, chalk pictures on the sidewalks or streets. Joanne Stamerra Hendricks uses erasers as a medium, and Jim Dingilian uses smoke. Dorsky Gallery Curatorial Projects, 11-03 45th Avenue, Long Island City, Queens – Holland Cotter.