Nuprl Lemma : setmem-emptyset
∀x:coSet{i:l}. ((x ∈ {}) ⇐⇒ False)
Proof
Definitions occuring in Statement : 
emptyset: {}, 
setmem: (x ∈ s), 
coSet: coSet{i:l}, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
false: False
Definitions unfolded in proof : 
rev_implies: P ⇐ Q, 
prop: ℙ, 
exists: ∃x:A. B[x], 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
so_apply: x[s], 
subtype_rel: A ⊆r B, 
top: Top, 
so_lambda: λ2x.t[x], 
member: t ∈ T, 
emptyset: {}, 
false: False, 
implies: P ⇒ Q, 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
coSet_wf, 
false_wf, 
emptyset_wf, 
set-subtype-coSet, 
setmem_wf, 
it_wf, 
mkset_wf, 
coSet-mem-Set-implies-Set, 
setmem-mkset
Rules used in proof : 
independent_functionElimination, 
productElimination, 
lambdaEquality, 
because_Cache, 
dependent_pairFormation, 
independent_isectElimination, 
hypothesisEquality, 
isectElimination, 
hypothesis, 
isect_memberEquality, 
voidElimination, 
applyEquality, 
functionExtensionality, 
sqequalRule, 
voidEquality, 
thin, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
sqequalHypSubstitution, 
cut, 
independent_pairFormation, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}x:coSet\{i:l\}.  ((x  \mmember{}  \{\})  \mLeftarrow{}{}\mRightarrow{}  False)
 Date html generated: 
2018_07_29-AM-09_53_07
 Last ObjectModification: 
2018_07_18-AM-10_42_59
Theory : constructive!set!theory
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