src/HOL/Transitive_Closure.thy

more "xsymbols" syntax;

(*  Title:      HOL/Transitive_Closure.thy
    ID:         $Id$
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1992  University of Cambridge

Relfexive and Transitive closure of a relation

rtrancl is reflexive/transitive closure;
trancl  is transitive closure
reflcl  is reflexive closure

These postfix operators have MAXIMUM PRIORITY, forcing their operands
to be atomic.
*)

Transitive_Closure = Lfp + Relation + 

constdefs
  rtrancl :: "('a * 'a) set => ('a * 'a) set"    ("(_^*)" [1000] 999)
  "r^* == lfp (%s. Id Un (r O s))"

  trancl :: "('a * 'a) set => ('a * 'a) set"    ("(_^+)" [1000] 999)
  "r^+ ==  r O rtrancl r"

syntax
  "_reflcl" :: "('a * 'a) set => ('a * 'a) set"    ("(_^=)" [1000] 999)
translations
  "r^=" == "r Un Id"

syntax (xsymbols)
  rtrancl :: "('a * 'a) set => ('a * 'a) set"    ("(_\\<^sup>*)" [1000] 999)
  trancl :: "('a * 'a) set => ('a * 'a) set"    ("(_\\<^sup>+)" [1000] 999)
  "_reflcl" :: "('a * 'a) set => ('a * 'a) set"    ("(_\\<^sup>=)" [1000] 999)

end