(* Title: HOL/Ord.thy
ID: $Id$
Author: Tobias Nipkow, Cambridge University Computer Laboratory
Copyright 1993 University of Cambridge
Type classes for order signatures and orders.
*)
Ord = HOL +
axclass
ord < term
consts
"op <" :: ['a::ord, 'a] => bool ("(_/ < _)" [50, 51] 50)
"op <=" :: ['a::ord, 'a] => bool ("(_/ <= _)" [50, 51] 50)
mono :: ['a::ord => 'b::ord] => bool (*monotonicity*)
min, max :: ['a::ord, 'a] => 'a
Least :: ('a::ord=>bool) => 'a (binder "LEAST " 10)
syntax
"op <" :: ['a::ord, 'a] => bool ("op <")
"op <=" :: ['a::ord, 'a] => bool ("op <=")
syntax (symbols)
"op <=" :: ['a::ord, 'a] => bool ("(_/ \\<le> _)" [50, 51] 50)
"op <=" :: ['a::ord, 'a] => bool ("op \\<le>")
defs
mono_def "mono(f) == (!A B. A <= B --> f(A) <= f(B))"
min_def "min a b == (if a <= b then a else b)"
max_def "max a b == (if a <= b then b else a)"
Least_def "Least P == @x. P(x) & (ALL y. P(y) --> x <= y)"
axclass order < ord
order_refl "x <= x"
order_trans "[| x <= y; y <= z |] ==> x <= z"
order_antisym "[| x <= y; y <= x |] ==> x = y"
order_less_le "x < y = (x <= y & x ~= y)"
end