Nuprl Lemma : fset-filter-is-empty
ā[T:Type]. ā[eq:EqDecider(T)]. ā[P:T ā¶ š¹]. ā[s:fset(T)].
uiff({x ā s | P[x]} = {} ā fset(T);¬(āx:T. (x ā s ā§ (āP[x]))))
Proof
Definitions occuring in Statement :
empty-fset: {}
,
fset-filter: {x ā s | P[x]}
,
fset-member: a ā s
,
fset: fset(T)
,
deq: EqDecider(T)
,
assert: āb
,
bool: š¹
,
uiff: uiff(P;Q)
,
uall: ā[x:A]. B[x]
,
so_apply: x[s]
,
exists: āx:A. B[x]
,
not: ¬A
,
and: P ā§ Q
,
function: x:A ā¶ B[x]
,
universe: Type
,
equal: s = t ā T
Definitions unfolded in proof :
uall: ā[x:A]. B[x]
,
member: t ā T
,
uiff: uiff(P;Q)
,
and: P ā§ Q
,
uimplies: b supposing a
,
not: ¬A
,
implies: P
ā Q
,
false: False
,
exists: āx:A. B[x]
,
prop: ā
,
so_apply: x[s]
,
so_lambda: λ2x.t[x]
,
top: Top
,
all: āx:A. B[x]
,
cand: A cā§ B
,
guard: {T}
,
iff: P
āā Q
,
rev_implies: P
ā Q
Lemmas referenced :
istype-universe,
fset-member_wf,
assert_wf,
fset-filter_wf,
not_wf,
exists_wf,
fset_wf,
bool_wf,
deq_wf,
mem_empty_lemma,
member-fset-filter,
fset-extensionality,
empty-fset_wf,
istype-void,
fset-member_witness,
assert_witness,
iff_weakening_uiff
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
Error :isect_memberFormation_alt,
introduction,
cut,
independent_pairFormation,
Error :lambdaFormation_alt,
thin,
hypothesis,
sqequalHypSubstitution,
independent_functionElimination,
voidElimination,
sqequalRule,
Error :productIsType,
extract_by_obid,
isectElimination,
hypothesisEquality,
Error :universeIsType,
applyEquality,
Error :lambdaEquality_alt,
dependent_functionElimination,
because_Cache,
Error :functionIsTypeImplies,
Error :inhabitedIsType,
Error :equalityIsType3,
baseClosed,
productEquality,
productElimination,
independent_pairEquality,
Error :isect_memberEquality_alt,
equalityTransitivity,
equalitySymmetry,
axiomEquality,
Error :functionIsType,
universeEquality,
functionExtensionality,
lambdaEquality,
cumulativity,
lambdaFormation,
voidEquality,
isect_memberEquality,
applyLambdaEquality,
hyp_replacement,
independent_isectElimination,
promote_hyp,
Error :dependent_pairFormation_alt
Latex:
\mforall{}[T:Type]. \mforall{}[eq:EqDecider(T)]. \mforall{}[P:T {}\mrightarrow{} \mBbbB{}]. \mforall{}[s:fset(T)].
uiff(\{x \mmember{} s | P[x]\} = \{\};\mneg{}(\mexists{}x:T. (x \mmember{} s \mwedge{} (\muparrow{}P[x]))))
Date html generated:
2019_06_20-PM-01_59_17
Last ObjectModification:
2018_10_06-PM-11_55_35
Theory : finite!sets
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