Nuprl Lemma : subtype_rel_b-union-left
∀[A,B:Type].  (A ⊆r (A ⋃ B))
Proof
Definitions occuring in Statement : 
b-union: A ⋃ B
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
b-union: A ⋃ B
, 
tunion: ⋃x:A.B[x]
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
pi2: snd(t)
Lemmas referenced : 
btrue_wf, 
ifthenelse_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaEquality, 
sqequalRule, 
imageMemberEquality, 
dependent_pairEquality, 
lemma_by_obid, 
hypothesis, 
hypothesisEquality, 
thin, 
instantiate, 
sqequalHypSubstitution, 
isectElimination, 
universeEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
axiomEquality, 
isect_memberEquality
Latex:
\mforall{}[A,B:Type].    (A  \msubseteq{}r  (A  \mcup{}  B))
Date html generated:
2016_05_13-PM-03_57_47
Last ObjectModification:
2015_12_26-AM-10_51_26
Theory : bool_1
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