Nuprl Lemma : regext-lemma1
∀T:Type. ∀f:T ⟶ coSet{i:l}. ∀B:coSet{i:l}.
  ((∃t:T. ∃g:set-dom(f t) ⟶ coSet{i:l}. seteq(B;mk-coset(set-dom(f t);g)))
  
⇒ (∀R:coSet{i:l} ⟶ coSet{i:l} ⟶ ℙ'
        (coSetRelation(R)
        
⇒  R:(B 
⇒ regext(mk-coset(T;f)))
        
⇒ (∃b:coSet{i:l}. ((b ∈ regext(mk-coset(T;f))) ∧  R:(B 
⇒ b) ∧ R:(B ─>> b))))))
Proof
Definitions occuring in Statement : 
regext: regext(a)
, 
onto-map: R:(A ─>> B)
, 
mv-map:  R:(A 
⇒ B)
, 
coset-relation: coSetRelation(R)
, 
setmem: (x ∈ s)
, 
seteq: seteq(s1;s2)
, 
set-dom: set-dom(s)
, 
mk-coset: mk-coset(T;f)
, 
coSet: coSet{i:l}
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
onto-map: R:(A ─>> B)
, 
regextfun: regextfun(f;w)
, 
cand: A c∧ B
, 
mk-set: f"(T)
, 
pi1: fst(t)
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
, 
Wsup: Wsup(a;b)
, 
top: Top
, 
uimplies: b supposing a
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
mk-coset: mk-coset(T;f)
, 
regext: regext(a)
, 
exists: ∃x:A. B[x]
, 
mv-map:  R:(A 
⇒ B)
, 
coset-relation: coSetRelation(R)
, 
prop: ℙ
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
seteq_inversion, 
setmem-mk-coset, 
onto-map_wf, 
equal_wf, 
setmem_functionality, 
all_wf, 
W_wf, 
setmem-coset, 
Wsup_wf, 
W-subtype-coW, 
regextfun_wf, 
seteq_weakening, 
setmem-mk-set-sq, 
seteq_wf, 
set-dom_wf, 
exists_wf, 
coset-relation_wf, 
set_wf, 
subtype_rel_self, 
coSet_wf, 
subtype_rel_dep_function, 
mv-map_wf, 
setmem_wf, 
setsubset-iff, 
regext_wf, 
transitive-set-iff, 
mk-coset_wf, 
regext-transitive
Rules used in proof : 
productEquality, 
independent_pairFormation, 
functionExtensionality, 
equalitySymmetry, 
equalityTransitivity, 
dependent_pairFormation, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
rename, 
setElimination, 
independent_isectElimination, 
setEquality, 
universeEquality, 
cumulativity, 
functionEquality, 
lambdaEquality, 
because_Cache, 
instantiate, 
applyEquality, 
sqequalRule, 
promote_hyp, 
allFunctionality, 
independent_functionElimination, 
productElimination, 
hypothesis, 
hypothesisEquality, 
isectElimination, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}T:Type.  \mforall{}f:T  {}\mrightarrow{}  coSet\{i:l\}.  \mforall{}B:coSet\{i:l\}.
    ((\mexists{}t:T.  \mexists{}g:set-dom(f  t)  {}\mrightarrow{}  coSet\{i:l\}.  seteq(B;mk-coset(set-dom(f  t);g)))
    {}\mRightarrow{}  (\mforall{}R:coSet\{i:l\}  {}\mrightarrow{}  coSet\{i:l\}  {}\mrightarrow{}  \mBbbP{}'
                (coSetRelation(R)
                {}\mRightarrow{}    R:(B  {}\mRightarrow{}  regext(mk-coset(T;f)))
                {}\mRightarrow{}  (\mexists{}b:coSet\{i:l\}.  ((b  \mmember{}  regext(mk-coset(T;f)))  \mwedge{}    R:(B  {}\mRightarrow{}  b)  \mwedge{}  R:(B  {}>>  b))))))
Date html generated:
2018_07_29-AM-10_07_29
Last ObjectModification:
2018_07_20-PM-05_48_17
Theory : constructive!set!theory
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