Entry Value
Name UNIQUE_SKOLEM_ALT
Conclusion !p. (!x. ?!y. p x y) <=> (?f. !x y. p x y <=> f x = y)
Constructive Proof Yes
Axiom
(\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 N|A
Constructive Lemmas
  • T
  • !a. ?x. x = a
  • !x. x = x
  • !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. t ==> t
  • !f y. (\x. f x) y = f y
  • !f g. (!x. f x = g x) ==> f = g
  • !t. (\x. t x) = t
  • !p x. p x ==> p ((@) p)
  • !p. (?!x. p x) <=> (?x. !y. p y <=> x = y)
  • !p. (?!x. p x) <=> (?x. p x) /\ (!x x'. p x /\ p x' ==> x = x')
  • !r. (!x. ?y. r x y) <=> (?f. !x. r x (f x))
  • F <=> (!p. p)
  • T <=> (\p. p) = (\p. p)
  • (~) = (\p. p ==> F)
  • (/\) = (\p q. (\f. f p q) = (\f. f T T))
  • (==>) = (\p q. p /\ q <=> p)
  • (!) = (\p. p = (\x. T))
  • (?) = (\p. !q. (!x. p x ==> q) ==> q)
  • (?) = (\p. p ((@) p))
  • (?!) = (\p. (?) p /\ (!x y. p x /\ p y ==> x = y))
  • Contained Package bool-class
    Comment Standard HOL library retrieved from OpenTheory
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