Nuprl Lemma : invert-union_wf
∀[A,B:Type]. ∀[x:A + B].  (invert-union(x) ∈ B + A)
Proof
Definitions occuring in Statement : 
invert-union: invert-union(x)
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
union: left + right
, 
universe: Type
Definitions unfolded in proof : 
invert-union: invert-union(x)
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
Lemmas referenced : 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
thin, 
unionEquality, 
lambdaFormation, 
unionElimination, 
inrEquality, 
inlEquality, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
axiomEquality, 
isect_memberEquality, 
because_Cache, 
universeEquality
Latex:
\mforall{}[A,B:Type].  \mforall{}[x:A  +  B].    (invert-union(x)  \mmember{}  B  +  A)
Date html generated:
2019_10_15-AM-11_07_01
Last ObjectModification:
2018_08_21-PM-01_58_51
Theory : general
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