Nuprl Lemma : regextfun_wf
∀[T:Type]. ∀[f:T ⟶ coSet{i:l}]. ∀[w:coW(T;x.set-dom(f x))].  (regextfun(f;w) ∈ coSet{i:l})
Proof
Definitions occuring in Statement : 
regextfun: regextfun(f;w)
, 
set-dom: set-dom(s)
, 
coSet: coSet{i:l}
, 
coW: coW(A;a.B[a])
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
ext-eq: A ≡ B
, 
Wsup: Wsup(a;b)
, 
mk-set: f"(T)
, 
regextfun: regextfun(f;w)
, 
and: P ∧ Q
, 
prop: ℙ
, 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
coSet_wf, 
subtype_rel_wf, 
set_wf, 
subtype_rel_weakening, 
coW-ext, 
set-dom_wf, 
coW_wf, 
fix_wf_coSet_system
Rules used in proof : 
equalitySymmetry, 
equalityTransitivity, 
axiomEquality, 
instantiate, 
universeEquality, 
functionExtensionality, 
rename, 
setElimination, 
dependent_pairEquality, 
productElimination, 
independent_isectElimination, 
functionEquality, 
productEquality, 
because_Cache, 
hypothesis_subsumption, 
isect_memberEquality, 
hypothesis, 
applyEquality, 
lambdaEquality, 
sqequalRule, 
hypothesisEquality, 
cumulativity, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[T:Type].  \mforall{}[f:T  {}\mrightarrow{}  coSet\{i:l\}].  \mforall{}[w:coW(T;x.set-dom(f  x))].    (regextfun(f;w)  \mmember{}  coSet\{i:l\})
Date html generated:
2018_07_29-AM-10_07_04
Last ObjectModification:
2018_07_20-PM-04_48_59
Theory : constructive!set!theory
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