(8steps total) PrintForm Definitions DiscreteMath Sections DiscrMathExt Doc
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Bijections have inverses.

At: bij imp exists inv2


  A,B:Type, f:(AB). Bij(ABf (g:(BA). InvFuns(A;B;f;g))

By: Repeat Def of InvFuns(A;B;f;g) | Bij(ABf) | Inj(ABf) | Surj(ABf)


Generated subgoal:

1 1. A : Type
2. B : Type
3. f : AB
4. a1,a2:Af(a1) = f(a2 a1 = a2
5. b:Ba:Af(a) = b
  g:(BA). (x:Ag(f(x)) = x) & (y:Bf(g(y)) = y)

7 steps

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applyfunctionuniverseequalimpliesandallexists
IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html

(8steps total) PrintForm Definitions DiscreteMath Sections DiscrMathExt Doc