Nuprl Lemma : axiom-listunion
∀[A,B:Type]. ∀[L:Unit ⋃ (A × B)].  L ∈ Unit supposing isaxiom(L) = tt
Proof
Definitions occuring in Statement : 
b-union: A ⋃ B
, 
bfalse: ff
, 
btrue: tt
, 
bool: 𝔹
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
isaxiom: if z = Ax then a otherwise b
, 
unit: Unit
, 
member: t ∈ T
, 
product: x:A × B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
b-union: A ⋃ B
, 
tunion: ⋃x:A.B[x]
, 
bool: 𝔹
, 
unit: Unit
, 
ifthenelse: if b then t else f fi 
, 
pi2: snd(t)
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
Lemmas referenced : 
bool_wf, 
btrue_wf, 
bfalse_wf, 
b-union_wf, 
unit_wf2, 
btrue_neq_bfalse
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
cut, 
sqequalHypSubstitution, 
imageElimination, 
productElimination, 
thin, 
unionElimination, 
equalityElimination, 
sqequalRule, 
hypothesisEquality, 
hypothesis, 
Error :equalityIsType3, 
Error :universeIsType, 
introduction, 
extract_by_obid, 
baseClosed, 
isectElimination, 
productEquality, 
Error :inhabitedIsType, 
universeEquality, 
equalitySymmetry, 
independent_functionElimination, 
voidElimination
Latex:
\mforall{}[A,B:Type].  \mforall{}[L:Unit  \mcup{}  (A  \mtimes{}  B)].    L  \mmember{}  Unit  supposing  isaxiom(L)  =  tt
Date html generated:
2019_06_20-PM-00_38_05
Last ObjectModification:
2018_10_06-AM-11_20_39
Theory : list_0
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