Entry Value
Name IMAGE_CONST
Conclusion !s c. IMAGE (\x. c) s = (if s = {} then {} else {c})
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
  • !t. ~ ~t <=> t
  • !t. (t <=> T) \/ (t <=> F)
  • !p c x y. p (if c then x else y) <=> (c ==> p x) /\ (~c ==> p y)
  • !p. ~(?x. p x) <=> (!x. ~p x)
  • !s t. ~(s = t) <=> (?x. x IN t <=> ~(x IN s))
  • !s. (?x. x IN s) <=> ~(s = {})
    		•
    Constructive Lemmas
  • T
  • !x y s. x IN y INSERT s <=> x = y \/ x IN s
  • !t1 t2. (if F then t1 else t2) = t2
  • !t1 t2. (if T then t1 else t2) = t1
  • !x y. x = y <=> y = x
  • !x y. x IN {y} <=> x = y
  • !x y. x = y ==> y = x
  • !x s. x INSERT s = {y | y = x \/ y IN s}
  • !x. ~(x IN {})
  • !x. x = x
  • !x. (@y. y = x) = x
  • !y s f. y IN IMAGE f s <=> (?x. y = f x /\ x IN s)
  • !t1 t2. t1 /\ t2 <=> t2 /\ t1
  • !t. (!x. t) <=> t
  • !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 x s. IMAGE f (x INSERT s) = f x INSERT IMAGE f s
  • !f y. (\x. f x) y = f y
  • !f g. (!x. f x = g x) <=> f = g
  • !f g. (!x. f x = g x) ==> f = g
  • !f s. IMAGE f s = {y | ?x. x IN s /\ y = f x}
  • !t. (\x. t x) = t
  • !f. IMAGE f {} = {}
  • !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 c x y. p (if c then x else y) <=> (c ==> p x) /\ (~c ==> p y)
  • !p. ~(?x. p x) <=> (!x. ~p x)
  • !s t. (!x. x IN s <=> x IN t) <=> s = t
  • !s t. ~(s = t) <=> (?x. x IN t <=> ~(x IN s))
  • !s t. (!x. x IN s <=> x IN t) ==> s = t
  • !s. (?x. x IN s) <=> ~(s = {})
  • F <=> (!p. p)
  • T <=> (\p. p) = (\p. p)
  • ~F <=> T
  • ~T <=> F
  • (~) = (\p. p ==> F)
  • COND = (\t t1 t2. @x. ((t <=> T) ==> x = t1) /\ ((t <=> F) ==> x = t2))
  • (/\) = (\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))
  • {} = {x | F}
    		•
    Contained Package set-thm
    Comment Standard HOL library retrieved from OpenTheory
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