Nuprl Lemma : null-bag-filter-map
∀[T,A:Type]. ∀[f:A ⟶ T]. ∀[p:T ⟶ 𝔹]. ∀[as:bag(A)].  null([x∈bag-map(f;as)|p[x]]) = null([x∈as|p[f x]])
Proof
Definitions occuring in Statement : 
bag-filter: [x∈b|p[x]], 
bag-map: bag-map(f;bs), 
bag: bag(T), 
null: null(as), 
bool: 𝔹, 
uall: ∀[x:A]. B[x], 
so_apply: x[s], 
apply: f a, 
function: x:A ⟶ B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
bag-filter: [x∈b|p[x]], 
bag-map: bag-map(f;bs), 
bag: bag(T), 
quotient: x,y:A//B[x; y], 
and: P ∧ Q, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
so_apply: x[s], 
compose: f o g, 
top: Top, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
uimplies: b supposing a, 
prop: ℙ, 
bag-null: bag-null(bs), 
so_lambda: λ2x.t[x], 
subtype_rel: A ⊆r B
Lemmas referenced : 
bool_wf, 
list_wf, 
filter_map, 
null-map, 
quotient-member-eq, 
permutation_wf, 
permutation-equiv, 
null_wf, 
filter_wf5, 
l_member_wf, 
equal_wf, 
equal-wf-base, 
bag_wf, 
bag-null_wf, 
assert_wf, 
bag-filter_wf, 
list-subtype-bag
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
pointwiseFunctionalityForEquality, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
pertypeElimination, 
productElimination, 
thin, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
cumulativity, 
hypothesisEquality, 
lambdaFormation, 
because_Cache, 
rename, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
setElimination, 
setEquality, 
hyp_replacement, 
applyLambdaEquality, 
productEquality, 
axiomEquality, 
functionEquality, 
universeEquality
Latex:
\mforall{}[T,A:Type].  \mforall{}[f:A  {}\mrightarrow{}  T].  \mforall{}[p:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[as:bag(A)].
    null([x\mmember{}bag-map(f;as)|p[x]])  =  null([x\mmember{}as|p[f  x]])
Date html generated:
2017_10_01-AM-08_45_43
Last ObjectModification:
2017_07_26-PM-04_30_53
Theory : bags
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