src/HOL/Library/Lattice_Syntax.thy

simplified proof

(* Author: Florian Haftmann, TU Muenchen *)

header {* Pretty syntax for lattice operations *}

(*<*)
theory Lattice_Syntax
imports Set
begin

notation
  inf  (infixl "\<sqinter>" 70) and
  sup  (infixl "\<squnion>" 65) and
  Inf  ("\<Sqinter>_" [900] 900) and
  Sup  ("\<Squnion>_" [900] 900) and
  top ("\<top>") and
  bot ("\<bottom>")

end
(*>*)