Entry |
Value |
Name |
BIJECTIVE_LEFT_RIGHT_INVERSE |
Conclusion |
!f. (!x y. f x = f y ==> x = y) /\ (!y. ?x. f x = y) <=>
(?g. (!y. f (g y) = y) /\ (!x. g (f x) = x)) |
Constructive Proof |
No |
Axiom |
!t. t \/ ~t
(\a. a = (\b. (\c. c) = (\c. c))) (\d. (\e. d e) = d)
(\a. a = (\b. (\c. c) = (\c. c)))
(\d. (\e. e = (\f. (\c. c) = (\c. c)))
(\g. (\h i.
(\j k.
(\l. l j k) =
(\m. m ((\c. c) = (\c. c)) ((\c. c) = (\c. c))))
h
i <=>
h)
(d g)
(d ((@) d)))) |
Classical Lemmas |
!t1 t2. ~(t1 ==> t2) <=> t1 /\ ~t2!p q. p ==> (?x. q x) <=> (?x. p ==> q x)!t. ~ ~t <=> t!t. (t <=> T) \/ (t <=> F)!f s t.
(!y. y IN t ==> (?x. x IN s /\ f x = y)) <=>
(?g. !y. y IN t ==> g y IN s /\ f (g y) = y)!f s t.
(!x. x IN s ==> f x IN t)
==> ((!x y. x IN s /\ y IN s /\ f x = f y ==> x = y) /\
(!y. y IN t ==> (?x. x IN s /\ f x = y)) <=>
(?g. (!y. y IN t ==> g y IN s) /\
(!y. y IN t ==> f (g y) = y) /\
(!x. x IN s ==> g (f x) = x)))!p. ~(?x. p x) <=> (!x. ~p x) |
Constructive Lemmas |
T!x y z. x = y /\ y = z ==> x = z!x y. x = y ==> y = x!x. x = x!x. x IN UNIV!t1 t2. ~(t1 ==> t2) <=> t1 /\ ~t2!p q. p /\ (!x. q x) <=> (!x. p /\ q x)!p q. p /\ (?x. q x) <=> (?x. p /\ q x)!p q. p ==> (?x. q x) <=> (?x. p ==> q x)!t. (!x. t) <=> t!t. ~ ~t <=> t!t. F /\ t <=> F!t. T /\ t <=> t!t. t /\ F <=> F!t. t /\ T <=> t!t. t /\ t <=> t!t. (F <=> t) <=> ~t!t. (T <=> t) <=> t!t. (t <=> F) <=> ~t!t. (t <=> T) <=> t!t. F ==> t <=> T!t. T ==> t <=> t!t. t ==> F <=> ~t!t. t ==> T <=> T!t. F \/ t <=> t!t. T \/ t <=> T!t. t \/ F <=> t!t. t \/ T <=> T!t. t \/ t <=> t!t. t ==> t!t. (t <=> T) \/ (t <=> F)!f y. (\x. f x) y = f y!f g. (!x. f x = g x) ==> f = g!f s t.
(!y. y IN t ==> (?x. x IN s /\ f x = y)) <=>
(?g. !y. y IN t ==> g y IN s /\ f (g y) = y)!f s t.
(!x. x IN s ==> f x IN t)
==> ((!x y. x IN s /\ y IN s /\ f x = f y ==> x = y) /\
(!y. y IN t ==> (?x. x IN s /\ f x = y)) <=>
(?g. (!y. y IN t ==> g y IN s) /\
(!y. y IN t ==> f (g y) = y) /\
(!x. x IN s ==> g (f x) = x)))!f s.
(!x y. x IN s /\ y IN s /\ f x = f y ==> x = y) <=>
(?g. !x. x IN s ==> g (f x) = x)!t. (\x. t x) = t!p a. (?x. a = x /\ p x) <=> p a!p x. x IN GSPEC p <=> p x!p x. x IN {y | p y} <=> p x!p x. p x ==> p ((@) p)!p. ~(?x. p x) <=> (!x. ~p x)!r. (!x. ?y. r x y) <=> (?f. !x. r x (f x))F <=> (!p. p)T <=> (\p. p) = (\p. p)~F <=> T~T <=> F(~) = (\p. p ==> F)(/\) = (\p q. (\f. f p q) = (\f. f T T))(==>) = (\p q. p /\ q <=> p)(\/) = (\p q. !r. (p ==> r) ==> (q ==> r) ==> r)(!) = (\p. p = (\x. T))(?) = (\p. !q. (!x. p x ==> q) ==> q)(?) = (\p. p ((@) p))UNIV = {x | T} |
Contained Package |
set-thm |
Comment |
Standard HOL library retrieved from OpenTheory |