Nuprl Lemma : strong-subtype-fset-member-type
∀[A,B:Type]. ∀[eq:EqDecider(B)].  ∀[s:fset(A)]. ∀[x:B].  x ∈ A supposing x ∈ s supposing strong-subtype(A;B)
Proof
Definitions occuring in Statement : 
fset-member: a ∈ s, 
fset: fset(T), 
deq: EqDecider(T), 
strong-subtype: strong-subtype(A;B), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
uimplies: b supposing a, 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
strong-subtype: strong-subtype(A;B), 
cand: A c∧ B, 
prop: ℙ, 
fset-member: a ∈ s, 
all: ∀x:A. B[x], 
guard: {T}, 
istype: istype(T), 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
fset: fset(T), 
quotient: x,y:A//B[x; y]
Lemmas referenced : 
fset-subtype, 
fset-member_wf, 
fset_wf, 
strong-subtype_wf, 
deq_wf, 
istype-universe, 
assert-deq-member, 
subtype_rel_list, 
strong-subtype-l_member-type, 
list_wf, 
set-equal_wf, 
set-equal-reflex, 
member_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
cut, 
hypothesisEquality, 
applyEquality, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
independent_isectElimination, 
hypothesis, 
productElimination, 
sqequalRule, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
Error :universeIsType, 
Error :inhabitedIsType, 
instantiate, 
universeEquality, 
dependent_functionElimination, 
independent_functionElimination, 
promote_hyp, 
Error :lambdaFormation_alt, 
pointwiseFunctionality, 
pertypeElimination, 
Error :productIsType, 
Error :equalityIstype, 
sqequalBase
Latex:
\mforall{}[A,B:Type].  \mforall{}[eq:EqDecider(B)].
    \mforall{}[s:fset(A)].  \mforall{}[x:B].    x  \mmember{}  A  supposing  x  \mmember{}  s  supposing  strong-subtype(A;B)
Date html generated:
2019_06_20-PM-01_58_36
Last ObjectModification:
2018_11_24-PM-06_40_37
Theory : finite!sets
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