Nuprl Lemma : b-union_wf
∀[A,B:Type].  (A ⋃ B ∈ Type)
Proof
Definitions occuring in Statement : 
b-union: A ⋃ B
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
universe: Type
Definitions unfolded in proof : 
b-union: A ⋃ B
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
Lemmas referenced : 
tunion_wf, 
bool_wf, 
ifthenelse_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesis, 
lambdaEquality, 
instantiate, 
hypothesisEquality, 
universeEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
because_Cache
Latex:
\mforall{}[A,B:Type].    (A  \mcup{}  B  \mmember{}  Type)
Date html generated:
2016_05_13-PM-03_20_59
Last ObjectModification:
2015_12_26-AM-09_10_35
Theory : union
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