Nuprl Lemma : filter-as-mapfilter
∀[L,P:Top].  (filter(P;L) ~ mapfilter(λx.x;P;L))
Proof
Definitions occuring in Statement : 
mapfilter: mapfilter(f;P;L), 
filter: filter(P;l), 
uall: ∀[x:A]. B[x], 
top: Top, 
lambda: λx.A[x], 
sqequal: s ~ t
Definitions unfolded in proof : 
mapfilter: mapfilter(f;P;L), 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
filter: filter(P;l), 
reduce: reduce(f;k;as), 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
uimplies: b supposing a, 
strict1: strict1(F), 
and: P ∧ Q, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
prop: ℙ, 
guard: {T}, 
or: P ∨ Q, 
squash: ↓T, 
map: map(f;as), 
list_ind: list_ind, 
has-value: (a)↓, 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
so_apply: x[s1;s2;s3], 
top: Top
Lemmas referenced : 
top_wf, 
map_nil_lemma, 
sqle_wf_base, 
map_cons_lemma, 
map-ifthenelse, 
is-exception_wf, 
base_wf, 
has-value_wf_base, 
sqequal-list_ind
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
baseClosed, 
independent_isectElimination, 
independent_pairFormation, 
lambdaFormation, 
hypothesis, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
inrFormation, 
imageMemberEquality, 
callbyvalueCallbyvalue, 
callbyvalueReduce, 
callbyvalueExceptionCases, 
inlFormation, 
imageElimination, 
exceptionSqequal, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
dependent_functionElimination, 
divergentSqle, 
sqleRule, 
sqleReflexivity, 
because_Cache, 
sqequalAxiom
Latex:
\mforall{}[L,P:Top].    (filter(P;L)  \msim{}  mapfilter(\mlambda{}x.x;P;L))
Date html generated:
2016_05_14-PM-01_29_21
Last ObjectModification:
2016_01_15-AM-08_28_17
Theory : list_1
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