Nuprl Lemma : setmem-fun-graph
∀b:coSet{i:l}. ∀f:(x:coSet{i:l} × (x ∈ b)) ⟶ coSet{i:l}.
  ((∀z1,z2:x:coSet{i:l} × (x ∈ b).  (seteq(fst(z1);fst(z2)) ⇒ seteq(f z1;f z2)))
  ⇒ (∀y:coSet{i:l}. ((y ∈ fun-graph(b;f)) ⇐⇒ ∃p:x:coSet{i:l} × (x ∈ b). seteq(y;(fst(p),f p)))))
Proof
Definitions occuring in Statement : 
fun-graph: fun-graph(b;f), 
orderedpairset: (a,b), 
setmem: (x ∈ s), 
seteq: seteq(s1;s2), 
coSet: coSet{i:l}, 
pi1: fst(t), 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
apply: f a, 
function: x:A ⟶ B[x], 
product: x:A × B[x]
Definitions unfolded in proof : 
true: True, 
squash: ↓T, 
top: Top, 
Wsup: Wsup(a;b), 
mk-set: f"(T), 
pi1: fst(t), 
set-dom: set-dom(s), 
pi2: snd(t), 
set-item: set-item(s;x), 
fun-graph: fun-graph(b;f), 
mk-coset: mk-coset(T;f), 
subtype_rel: A ⊆r B, 
so_apply: x[s], 
so_lambda: λ2x.t[x], 
exists: ∃x:A. B[x], 
rev_implies: P ⇐ Q, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
member: t ∈ T, 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
true_wf, 
squash_wf, 
seteq_weakening, 
seteq_functionality, 
seteq-orderedpairs-iff, 
seteqweaken_wf, 
setmem-mk-coset, 
subtype_rel_self, 
mem-mk-set_wf2, 
mk-coset_wf, 
setmem-iff, 
coSet_subtype, 
subtype_coSet, 
all_wf, 
pi1_wf, 
orderedpairset_wf, 
seteq_wf, 
coSet_wf, 
exists_wf, 
fun-graph_wf, 
setmem_wf
Rules used in proof : 
levelHypothesis, 
baseClosed, 
imageMemberEquality, 
natural_numberEquality, 
equalityTransitivity, 
imageElimination, 
equalitySymmetry, 
hyp_replacement, 
addLevel, 
because_Cache, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
dependent_pairEquality, 
dependent_pairFormation, 
independent_functionElimination, 
dependent_functionElimination, 
hypothesis_subsumption, 
functionEquality, 
applyEquality, 
lambdaEquality, 
sqequalRule, 
cumulativity, 
productEquality, 
instantiate, 
productElimination, 
hypothesis, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
independent_pairFormation, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}b:coSet\{i:l\}.  \mforall{}f:(x:coSet\{i:l\}  \mtimes{}  (x  \mmember{}  b))  {}\mrightarrow{}  coSet\{i:l\}.
    ((\mforall{}z1,z2:x:coSet\{i:l\}  \mtimes{}  (x  \mmember{}  b).    (seteq(fst(z1);fst(z2))  {}\mRightarrow{}  seteq(f  z1;f  z2)))
    {}\mRightarrow{}  (\mforall{}y:coSet\{i:l\}.  ((y  \mmember{}  fun-graph(b;f))  \mLeftarrow{}{}\mRightarrow{}  \mexists{}p:x:coSet\{i:l\}  \mtimes{}  (x  \mmember{}  b).  seteq(y;(fst(p),f  p)))))
Date html generated:
2018_07_29-AM-10_09_14
Last ObjectModification:
2018_07_18-PM-09_37_41
Theory : constructive!set!theory
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