(7steps total) PrintForm Definitions DiscreteMath Sections DiscrMathExt Doc
IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At: union sigma inverses 1 1
1. A : Type
2. B : Type
3. x : A+B
  sigma_to_union(union_to_sigma(x)) = x
By: New:[a | b] Analyze-1

Generated subgoals:

1 3. a : A
  sigma_to_union(union_to_sigma(inl(a))) = inl(a)  A+B
1 step
2 3. b : B
  sigma_to_union(union_to_sigma(inr(b))) = inr(b)  A+B
1 step

About:
unioninlinrapplyuniverseequal
IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html

(7steps total) PrintForm Definitions DiscreteMath Sections DiscrMathExt Doc