anchor.diff:    let (langle,   rangle)   as lrangle   = (Text "<", Text ">")
     let (lbrace,   rbrace)   as lrbrace   = (Text "{", Text "}")
     let (lbracket, rbracket) as lrbracket = (Text "[", Text "]")
  +
     let squote = Text "'"
     let lrsquote = (squote, squote)
     let dquote = Text "\""
  
positive.code: [<AutoOpen>]
  module Util =
    let inline (^) x = x
    let inline K x _ = x
    let inline flip f x y = f y x
    let inline force (s: Lazy<_>) = s.Force ()
  
  
negative.code:     width' d ^ fun w -> if p f w then t f else txt ^ spaces ^ f-w
  
    let fillBreak n d = mkFill (<) (flip nest linebreak) n d
    let fill n d = mkFill (<=) (constant empty) n d
  
    let rec flatten doc = delay ^ fun () ->
      match doc with
  