| ESet (x, e) => dBox [string x, space 1, string "=", space 1, p_exp e]
| EGet (x1, x2, e) => dBox [dBox [string x1, space 1, string "<-",
space 1, string x2, string ";", space 1],
p_exp e]
| ESeq es => dBox (valOf (foldr (fn (e, NONE) => SOME [p_exp e]
| ESet (x, e) => dBox [string x, space 1, string "=", space 1, p_exp e]
| EGet (x1, x2, e) => dBox [dBox [string x1, space 1, string "<-",
space 1, string x2, string ";", space 1],
p_exp e]
| ESeq es => dBox (valOf (foldr (fn (e, NONE) => SOME [p_exp e]