Nuprl Lemma : fset-null_wf
∀[T:Type]. ∀[s:fset(T)].  (fset-null(s) ∈ 𝔹)
Proof
Definitions occuring in Statement : 
fset-null: fset-null(s), 
fset: fset(T), 
bool: 𝔹, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
fset: fset(T), 
quotient: x,y:A//B[x; y], 
and: P ∧ Q, 
fset-null: fset-null(s), 
prop: ℙ, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
cons: [a / b], 
top: Top, 
set-equal: set-equal(T;x;y), 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
uimplies: b supposing a, 
not: ¬A, 
false: False
Lemmas referenced : 
bool_wf, 
equal-wf-base, 
list_wf, 
set-equal_wf, 
fset_wf, 
equal_wf, 
list-cases, 
null_nil_lemma, 
btrue_wf, 
product_subtype_list, 
null_cons_lemma, 
cons_member, 
l_member_wf, 
member-implies-null-eq-bfalse, 
nil_wf, 
btrue_neq_bfalse, 
bfalse_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
pointwiseFunctionalityForEquality, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
pertypeElimination, 
productElimination, 
thin, 
productEquality, 
isectElimination, 
cumulativity, 
hypothesisEquality, 
because_Cache, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
universeEquality, 
lambdaFormation, 
dependent_functionElimination, 
independent_functionElimination, 
unionElimination, 
promote_hyp, 
hypothesis_subsumption, 
rename, 
voidElimination, 
voidEquality, 
inlFormation, 
independent_isectElimination
Latex:
\mforall{}[T:Type].  \mforall{}[s:fset(T)].    (fset-null(s)  \mmember{}  \mBbbB{})
Date html generated:
2017_04_17-AM-09_19_53
Last ObjectModification:
2017_02_27-PM-05_23_26
Theory : finite!sets
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