Nuprl Lemma : bag-void-sq-empty
∀[T:Type]. ∀x:bag(T). x ~ {} supposing ¬T
Proof
Definitions occuring in Statement : 
empty-bag: {}
, 
bag: bag(T)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
universe: Type
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
implies: P 
⇒ Q
, 
bag: bag(T)
, 
quotient: x,y:A//B[x; y]
, 
and: P ∧ Q
, 
or: P ∨ Q
, 
nil: []
, 
it: ⋅
, 
empty-bag: {}
, 
cons: [a / b]
, 
not: ¬A
, 
false: False
, 
prop: ℙ
Lemmas referenced : 
equal-empty-bag, 
list-cases, 
product_subtype_list, 
empty-bag_wf, 
list_wf, 
permutation_wf, 
istype-void, 
bag_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
lambdaFormation_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_functionElimination, 
independent_functionElimination, 
pointwiseFunctionalityForEquality, 
because_Cache, 
hypothesis, 
sqequalRule, 
pertypeElimination, 
promote_hyp, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
inhabitedIsType, 
unionElimination, 
hypothesis_subsumption, 
voidElimination, 
equalityIstype, 
productIsType, 
universeIsType, 
sqequalBase, 
axiomSqEquality, 
functionIsType, 
lambdaEquality_alt, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
functionIsTypeImplies, 
instantiate, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}x:bag(T).  x  \msim{}  \{\}  supposing  \mneg{}T
Date html generated:
2019_10_15-AM-10_59_53
Last ObjectModification:
2019_08_15-AM-10_32_40
Theory : bags
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