Nuprl Lemma : do-apply-p-co-filter
∀[T:Type]. ∀[P:T ⟶ ℙ]. ∀[f:∀x:T. Dec(P[x])]. ∀[x:T].
  do-apply(p-co-filter(f);x) = x ∈ T supposing ↑can-apply(p-co-filter(f);x)
Proof
Definitions occuring in Statement : 
p-co-filter: p-co-filter(f), 
do-apply: do-apply(f;x), 
can-apply: can-apply(f;x), 
assert: ↑b, 
decidable: Dec(P), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s], 
all: ∀x:A. B[x], 
function: x:A ⟶ B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
p-co-filter: p-co-filter(f), 
do-apply: do-apply(f;x), 
can-apply: can-apply(f;x), 
uimplies: b supposing a, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
subtype_rel: A ⊆r B, 
all: ∀x:A. B[x], 
top: Top, 
implies: P ⇒ Q, 
decidable: Dec(P), 
or: P ∨ Q, 
isl: isl(x), 
outl: outl(x), 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
false: False, 
btrue: tt
Lemmas referenced : 
all_wf, 
decidable_wf, 
assert_wf, 
can-apply_wf, 
p-co-filter_wf, 
subtype_rel_dep_function, 
top_wf, 
subtype_rel_union, 
false_wf, 
true_wf, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
isect_memberEquality, 
isectElimination, 
thin, 
hypothesisEquality, 
axiomEquality, 
hypothesis, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
lemma_by_obid, 
lambdaEquality, 
applyEquality, 
functionEquality, 
cumulativity, 
universeEquality, 
unionEquality, 
independent_isectElimination, 
lambdaFormation, 
voidElimination, 
voidEquality, 
unionElimination, 
dependent_functionElimination, 
independent_functionElimination
Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[f:\mforall{}x:T.  Dec(P[x])].  \mforall{}[x:T].
    do-apply(p-co-filter(f);x)  =  x  supposing  \muparrow{}can-apply(p-co-filter(f);x)
Date html generated:
2016_05_15-PM-03_31_08
Last ObjectModification:
2015_12_27-PM-01_11_10
Theory : general
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